Linear Slide Rules

Between 1614 and 1622, John Napier discovered logarithms, Edmund Gunter devised a scale on which numerals could be multiplied and divided by measuring the distance between two logarithmic numbers with a pair of dividers, and William Oughtred put two such scales alongside each other, moving one on a slide so that the distance between the numbers could be read off directly. The speed with which these developments unfolded suggests the power that logarithms provided for reducing the tedium of calculation. By the 1680s, the English used slide rules in carpentry and in gauging (estimating liquid volumes)—the instruments were quite helpful for determining excise taxes on barrels of liquor.

It was not until the late eighteenth century that slide rules were commonly utilized in the manufacture of machines and machine tools, most notably by James Boulton and James Watt. Several more decades passed before slide rule use became widespread throughout Europe. French artillery officer Amedée Mannheim fostered acceptance of the rectangular or linear form of the instrument in 1851 by standardizing the general types of scales and the order in which the scales were arranged. Mannheim also developed the cursor or indicator, which made it easier to read results from two scales that were not adjacent to each other. By the 1870s, German companies made slide rules one of the first consumer products to be fashioned out of plastic (specifically, sheets of celluloid laminated to a wooden frame), and they built dividing engines that permitted mass production of the scales engraved on slide rules. In the United States in the 1890s, Keuffel & Esser of New York City pioneered first the import and then the domestic manufacture of linear slide rules. Numerous other companies entered the market in the 20th century.

Image of an advertisement for an Engineers Slide Rule
Keuffel & Esser was one of the first American firms to import linear slide rules from Europe. Catalogue and Price List of Keuffel and Esser, 13th ed. (New York, 1880), 71. NMAH Trade Literature Collection, Smithsonian Institution Libraries. AHB2013q009220

A quick tour of what you can expect to see on a slide rule starts with the C and D scales, which both represent the standard number line. To multiply two numbers, set the 1 on the C scale above the first number to be multiplied on the D scale. Look at the second number to be multiplied on the C scale; the number below it on the D scale is the answer. For example, to multiply 2 by 3, set 1 on C over 2 on D, and then look below 3 on C to see the answer 6 on D. Division is accomplished by reversing the process. To calculate 6 ÷ 3, set 3 on C over 6 on D, then look at 1 on C to see the answer 2 on D. To deal with numbers larger than 10 or smaller than 1, the user must mentally move the decimal point. Slide rule users also had to be able to estimate distances between marks on the scales, since there was no way to include all of the digits needed to solve a problem such as 3.14 X 2.7. (On linear and circular slide rules, the answer is "approximately 8.48." Web sites on the Resources page provide more detailed training in using slide rules.)

Instructions for multiplying two numbers on a slide rule frpm the Eugene Dietzgen Co.,
Instructions for multiplying two numbers on a slide rule. Eugene Dietzgen Co., Self-teaching Instruction Manual [for] Maniphase Slide Rule (Chicago, [1950s]), 4. NMAH Mathematics Collection, cat. no. 1988.0367.02. AHB2013q009216

The basic process for setting up and solving problems is the same for operations on other scales. If the numbers used in the calculation produce a result off the ends of the scales, a user employs the CI and DI scales, which put the number line in inverse, or reverse, order. If the numbers still extend past the end of the instrument, the user may try the "folded" CF and DF scales, which start numbering at π instead of at 1. The A and B scales are number lines of squares, so they are used with the C or D scales to square (or take the square root of) a number. The K scale provides cubes and cube roots. L scales represent common logarithms, S scales give sines and cosines, and T scales indicate tangents.

This is an eight-inch, four-sided boxwood slide rule used for measuring and taxing barrels of liquid. On one end of the rule, the slides on each side have been labeled with the four Roman numerals, I, II, III, and IV.
Description
This is an eight-inch, four-sided boxwood slide rule used for measuring and taxing barrels of liquid. On one end of the rule, the slides on each side have been labeled with the four Roman numerals, I, II, III, and IV. On side I, the base has logarithmic scales that run from 1 to 8 and from 8 to 100. It is labeled Seg St (Segments Standing) at the top left and SS at the bottom right. The slide has two identical C scales, logarithmically divided from 1 to 9. This side was used to estimate the volume of a barrel that was standing vertically and partially filled. The back of the slide lists calculating factors used in computing taxes on various liquors. For instance, the duty on one barrel of vinegar was equivalent to the duty on 7.56 barrels of small beer.
On side II, the base has logarithmic scales that run from 0 to 4 and from 4 to 100. The bottom right corner is labeled SL (Segments Lying) for estimating the volume of a partially filled barrel lying on its side. The slide has two identical B scales, logarithmically divided from 1 to 10. The point 231 is marked W, showing the number of cubic inches in a wine gallon, and pi (314) is marked with a C. The back of the slide has a table of gauge points for converting between volumes in cubic inches and numbers of gallons for substances in square or circular containers.
On side III, the base has an A scale, logarithmically divided from 1 to 10, and an MD (Malt Depth) scale that runs logarithmically in the opposite direction from somewhat less than 3 to 20. Point 2150 on the A scale is marked MB, for the number of cubic inches in a malt bushel, and point 282 is marked A, for the number of cubic inches in an ale gallon. The slide has two identical B scales, logarithmically divided from 1 to 9. The back of the slide has a scale of inches, a scale labeled Spheroid, and a scale labeled 2d Variety. These scales are for determining the diameters of two different shapes of barrels. Underneath the slide is marked: LEWIS & BRIGGS : Makers. No. 52. BOW. LANE. Cheapside. LONDON.
On side IV, the base has a D scale, logarithmically divided from 1 to 3.2 and from 3.2 to 10. Point 17.15 is marked WG, for the diameter in inches of a cylinder that contains one gallon of wine when filled to a depth of one inch. Point 18.95 is marked AG for the diameter of a cylinder containing one gallon of ale. Point 46.3 is marked MS, for the side of a square vessel that contains a solid bushel per inch of depth, and point 52.32 is marked MR, for the side of a square vessel that contains a malt bushel per inch of depth.
The slide has two identical C scales, logarithmically divided from 1 to 10. The back of the slide has a table of divisors for converting between volumes in cubic inches and numbers of gallons for substances in square or circular containers. The numbers in this table are squares of the gauge points in the table on the back of the slide on side II. Underneath the slide is marked: Willm. Wright : April. 30. 1795.
According to Gloria Clifton, the firm of Lewis & Briggs operated in London from at least 1795 to 1799. The Smithsonian acquired this object in 1961.
References: Colin Barnes, "The Customs and Excise Gauging Slide Rule," Journal of the Oughtred Society 4, no. 2 (1995): 53–57; Ron Manley, "Gauging," http://www.sliderules.info/a-to-z/gauging.htm; Gloria Clifton, Directory of British Scientific Instrument Makers (London: National Maritime Museum, 1995), 167.
Location
Currently not on view
date made
1795
maker
Lewis & Briggs
ID Number
MA.319510
catalog number
319510
accession number
239015
This is a two-foot, two-fold boxwood rule with a brass hinge and endpieces. Half of one side is a slide rule with A and D scales on the base and B and C scales on the slide.
Description
This is a two-foot, two-fold boxwood rule with a brass hinge and endpieces. Half of one side is a slide rule with A and D scales on the base and B and C scales on the slide. As with MA.306697.01, the C scale is the same as the A and B scales (the square of the D scale), instead of the same as the D scale, as on modern Mannheim slide rules. Below the D scale is marked: SQUARE CYLINDER GLOBE (3 times) ROUTLEDGE'S ENGINEER.
The first three marks form headings for the tables on the other half of this side when the instrument is folded. The tables give conversion factors from the volumes of geometric solids to units of volume, in both the "old" and imperial systems; conversion factors from the volumes of geometric solids to the weights in pounds of various substances; the areas of polygons from 5 to 12 sides; the gauge points of a circle; and gauge points for pumping engines, to find the diameters of steam cylinders that will work pumps of specified diameter at 7 pounds per square inch.
The other side has a scale of 24 inches along one edge, divided to sixteenths of an inch for 9 inches and to eighths of an inch for the rest of the scale. There are also scales for making scale drawings that are 1, 3/4, 1/2, and 1/4 inches to the foot. This side is marked: T. ASTON THE ORIGINAL MAKER WARRANTED. One outside edge has scales for 10 and 12 parts to the inch; the other outside edge divides one foot into 100 parts.
This form of slide rule was invented by Joshua Routledge, a seller of iron goods, in 1808 or 1809. He discussed it in the 1813 (4th) edition of Instructions for the Engineer's Improved Sliding Rule. According to Gloria Clifton, there were two rule makers named Thomas Aston, presumably a father and son, who were in business at various addresses in Birmingham, England, from 1818 to 1862. The references to pre-imperial system units of measure suggest the rule might have been made shortly after the imperial system was adopted in 1824. This instrument was found in the home of Grace Speer, granddaughter of Alfred Speer (1823–1910), an inventor and wine merchant in Passaic, N.J.
References: John V. Knott, "Joshua Routledge 177[3]–1829," Journal of the Oughtred Society 4, no. 2 (1995): 25; Philip E. Stanley, "Carpenters' and Engineers' Slide Rules: Routledges' Rule," Chronicle of the Early American Industries Association 37, no. 2 (1984): 25–27; Gloria Clifton, Directory of British Scientific Instrument Makers (London: National Maritime Museum, 1995), 11–12; accession file.
Location
Currently not on view
date made
1824-1862
maker
Aston, T.
ID Number
1981.0934.01
catalog number
1981.0934.01
accession number
1981.0934
This is a twelve-inch, four-sided boxwood slide rule used in England for measuring and taxing barrels of liquid. Each of the four slides has a brass guide at one end, and the various special points on the rules are marked with inset brass pegs.
Description
This is a twelve-inch, four-sided boxwood slide rule used in England for measuring and taxing barrels of liquid. Each of the four slides has a brass guide at one end, and the various special points on the rules are marked with inset brass pegs. On one side, the base has a D scale, logarithmically divided from 1 to 3.2 and from 3.2 to 10. Point 18.789 is marked G, the circular gauge point, for determining the mean diameter of a barrel. Point 46.3 is marked MS, for the side of a square vessel that contains a solid bushel per inch of depth, and point 52.32 is marked MR, for the side of a square vessel that contains a malt bushel per inch of depth. The slide has two identical B scales, logarithmically divided from 1 to 10. Point 277.42 is marked G for the imperial gallon.
On the second side, the base has logarithmic scales that run from 1 to 8 and from 8 to 100. It is labeled SEGT ST (Segments Standing) at the top left and SS at the bottom right. The slide has two identical C scales, logarithmically divided from 1 to 9. This side was used to estimate the volume of a barrel that was standing vertically and partially filled. The back of the slide lists gauge points, divisors, and factors for circles for malt and for gall (another substance used in making alcoholic beverages) in circular and square containers.
On the third side, the base has an A scale, logarithmically divided from 1 to 10, and an MD (Malt Depth) scale that runs logarithmically in the opposite direction from somewhat less than 3 to 20. Point 2219 is marked B, for the number of cubic inches in a bushel under the imperial system of measurement, and point 277.42 is marked G, for the imperial gallon. The slide has two identical C scales, logarithmically divided from 1 to 9. The back of the slide has a scale of inches, a scale labeled SPH[EROI]D, and a scale labeled 2D VAR[IETY]. These scales are for determining the diameters of two different shapes of barrels. Underneath the slide is marked: COOK. MAKER TO THE HONBLE BOARD OF EXCISE. LATE WELLINGTON CROWN COURT SOHO LONDON NO 2950.
On the fourth side, the base has logarithmic scales that run from 0 to 4 and from 4 to 100. It is labeled SEGT LY (Segments Lying) at the top left and SL at the bottom right. The slide has two identical B scales, logarithmically divided from 1 to 9. Underneath the slide, points 3.9 and 99 are connected by a line marked with H.
The use of the Imperial system of units dates this slide rule to after 1824. It is of the style developed by Thomas Everard in 1683 and, at 12 inches, represents one of the two standard "pocket" sizes (the other was 9"). Laban Cook(e) succeeded Alexander Wellington (d. 1825) as a Maker to the English Board of Excise and remained in business until 1834. Compare to the older rule for gauging and ullage (the amount a container is lacking to be full), 319510.
References: D. Baxandall, Catalogue of the Collections in the Science Museum: Mathematics I. Calculating Machines and Instruments (London, 1926), 42; Colin Barnes, "The Customs and Excise Gauging Slide Rule," Journal of the Oughtred Society 4, no. 2 (1995): 53–57; Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 72, 245; Gloria Clifton, Dictionary of British Scientific Instrument Makers (London: National Maritime Museum, 1995), 64.
Location
Currently not on view
date made
1825-1834
maker
Cook, Laban
ID Number
1980.0588.04
catalog number
1980.0588.04
accession number
1980.0588
From the late 18th to the mid-19th centuries, British engineers began to use slide rules. This ivory and silver instrument is a four-fold engineer's rule that unfolds to a length of 24 inches.
Description
From the late 18th to the mid-19th centuries, British engineers began to use slide rules. This ivory and silver instrument is a four-fold engineer's rule that unfolds to a length of 24 inches. On half of one side is a slide rule with A and D scales on the base and B and C scales on the slide. The A and D scales seem to run continuously, although the slide only moves on the second six inches of the rule.
The words IRON and ROPE appear several times along the edge of the A scale. Along the edge of the D scale is marked: DESCRIPTION SQUARE CYL[I]ND[ER] GLOBE SQUARE CYL[I]ND[ER] WEIGHT STRAIN WORK INCLIN[E] POLYGON SIDE GOVERNORS H[ORSE]P[OWER] ENGIN[E]S STE[A]M TEM[PERATURE]. When the rule is folded, these markings correspond to the tables on the other half of the instrument.
The other half of this side has a table of gauge points for the A scale. Instructions printed on the rule suggest that calculations on the slide rule were intended to be made with calipers. Additional tables and instructions for working with ropes and chains are on this half, which is marked: IMPROVED & ARRANG[E]D (/) BY RT HAWTHORN (/) CIVIL ENGINEER (/) NEWCASTLE TYNE.
The other side has a scale of 24 inches divided to eighths of an inch along the edge. The metal joint has a protractor divided in increments of 5 degrees and marked by tens from 0 to 180. When the instrument is folded around the joint, there are tables for the extreme strain possible in bars and beams of various substances and for equivalent measures. The joint is marked: G. R. STEPHENSON (/) ENGINEER (/) Adam Pensom.
In 1832 civil engineer Robert Hawthorn (1796–1867) designed a new form of slide rule for manufacturing locomotives and other engines. In 1859 dealers sold the rule for 5 shillings and 6 pence. The names on the joint may refer to the British civil engineer George Robert Stephenson (1819–1905), nephew to the engineer George Stephenson (1781–1848), who sought mechanical advice from Hawthorn's father, and to Adam Pensom (b. 1824), who was a retired gas engineer living in London, according to the 1881 British census. The Smithsonian acquired this object in 1973.
References: Robert Hawthorn, Instructions for the Use of the Mechanics' Sliding Rule (Newcastle-upon-Tyne, 1841), available online at http://www.physics.uq.edu.au/physics_museum/hawthorne/; "Mr. Robert Hawthorn," Minutes of the Proceedings of the Institution of Civil Engineers 27 (1867–1868): 590–592; advertisement by John Archbutt, The Mechanics' Magazine, n.s., 1, no. 10 (March 4, 1859): 486; Peter M. Hopp, Joint Slide Rules (Jeremy Mills Publishing: Lindley, Huddersfield, West Yorkshire, 2009).
Location
Currently not on view
date made
after 1832
maker
Hawthorn, Robert
ID Number
MA.306697.01
accession number
306697
catalog number
306697.01
One of the first types of slide rules sold and made in the United States was the carpenter's rule, used for calculations relating to timber, which was one of the country's major early exports. This rule is marked on the lower arm: S. A. JONES & CO. (/) HARTFORD–CON.
Description
One of the first types of slide rules sold and made in the United States was the carpenter's rule, used for calculations relating to timber, which was one of the country's major early exports. This rule is marked on the lower arm: S. A. JONES & CO. (/) HARTFORD–CON. (/) WARRANTED BOX WOOD. Solomon A. Jones made carpentry tools in Hartford, Conn., from 1838 to 1841. Compare to 1987.0771.01, a British carpenter's rule of the same period. The collections include an image of someone holding the rule (see 2003.0215.02).
This boxwood carpenter’s rule has a brass joint, metal caps at the ends of the arms, and a brass slide. The front of the slide has two identical logarithmic scales labeled B and C. Above is an identical logarithmic scale on the arm; this scale is labeled A. All three of these scales have a double cycle of logarithms, like the A and B scales on a Mannheim rule. Below the C scale on the arm is a scale labeled D and also GIRT LINE, which is divided logarithmically and runs from 4 to 40 (in other words, this is not the D or principal scale of Mannheim slide rules). The girt line can be used with other scales to estimate the volume of timber available from a log.
Underneath the slide is imprinted the number 33. The back of the slide is also stamped with the number 33 and is somewhat crudely marked with a twelve-inch ruler, divided to eighths of an inch. The lower arm contains scales for making scale drawings that are 1/4, 1/2, 3/4, and 1 inch to the foot. The units on the 1/4-inch chain scale appear to be numbered erroneously after 18 (e.g., the next numbered division after 18 is 10 rather than 20). Along the edge is another twelve-inch scale, divided to eighths of an inch.
The other side of the rule has a scale of 24 inches along one edge, divided to sixteenths of an inch. One arm has a scale labeled by twos from 34 to zero and is marked M. A number for 31 is between 32 and 30, and the number for 6 is omitted.
The other arm has a scale marked E and labeled by twos from 24 to zero. The number 24 appears twice, and 6 is omitted. The M and E scales were used in cutting polygonal sections of wood. The outside edge has two scales, each dividing one foot into 100 parts.
References: Kenneth D. Roberts, Introduction to Rule Collecting (Hartford, Conn.: The Bond Press, Inc., 1982); "Solomon A. Jones & Co.," The Davistown Museum, http://www.davistownmuseum.org/bioSAJones.html.
Location
Currently not on view
date made
1838-1841
maker
S. A. Jones & Co.
ID Number
2003.0216.01
accession number
2003.0216
catalog number
2003.0216.01
In the 17th century, the British author Henry Coggeshall published a pamphlet describing a linear rule especially for calculations relating to timber.
Description
In the 17th century, the British author Henry Coggeshall published a pamphlet describing a linear rule especially for calculations relating to timber. As one of the major early exports of the British colonies in North America and later the United States was timber, it is not surprising that a form of Coggeshall’s rule, called the carpenter’s rule, came to be one of the first slide rules used and sold in this country. The carpenter’s rule was made from two wooden one-foot rules that were held together at one end by a metal joint. Unfolded, one side became a simple two-foot measuring rule. The upper part of the other side contained a groove that held a brass slide, with logarithmic scales on the upper and lower edges of both the slide and the adjacent parts of the groove. The outer edges and lower part of this side commonly were marked with other scales of use to carpenters and spar-makers.
This boxwood carpenter’s rule has a brass joint, a brass cap at the end of one arm, and a brass slide. The cap and part of the wood have worn away at the end of the upper arm, which has the slider. The slide has two identical logarithmic scales labeled B and C. Above it is an identical logarithmic scale on the arm; this scale is labeled A. All three of these scales have a double cycle of logarithms. Below the C scale on the arm is a scale labeled D and also GIRT LINE, which is divided logarithmically and runs from 4 to 40 (in other words, this is not the D or principal scale of modern Mannheim slide rules). The girt line can be used in conjunction with other scales to estimate the volume of timber available from a log. The rule is marked: T. BRADBURN & SON MAKERS WARRANTED BEST BOX.
The lower arm contains scales for making scale drawings that are 1/4, 3/8, 1/2, 5/8, 3/4, and 1 inch to the foot. The other side has a scale of 24 inches along one edge, divided to sixteenths of an inch for 6 inches and to eighths of an inch for the rest of the scale. One arm has a scale numbered by twos from 46 to zero and labeled SQUARE LINE M. The other arm has a scale labeled by twos from 36 to zero and marked E. The M and E scales were used while cutting polygonal sections of wood. The outside edge has two scales, each dividing one foot into 100 parts. All of the scales are crudely divided.
According to Gloria Clifton, George Thomas Bradburn made rules in Birmingham, England, from 1841 to 1852. According to W. L.Goodman, Thomas Bradburn was in business making rules in Birmingham from 1839 to 1870. Thomas Bradburn & Son was in business in Birmingham from 1863 to 1876. Hence, this carpenter’s rule would seem to date from the period 1863–1876. This instrument resembles a carpenter’s rule sold in the United States by S. A. Jones & Co. of Hartford, Conn. (2003.0216.01).
References: Gloria Clifton, Directory of British Scientific Instrument Makers, 1550–1851 (London: National Maritime Museum, 1995), 36; W. L. Goodman, British Planemakers from 1700 (Mendham, N.J.: Astragal Press, 1993), 185–186; Bruce Babcock, "A Guided Tour of an 18th-Century Carpenter's Rule," Journal of the Oughtred Society 3, no. 1 (1994): 26–34.
Location
Currently not on view
date made
1863-1876
maker
T. Bradburn & Son
ID Number
1987.0777.01
accession number
1987.0777
catalog number
1987.0777.01
By the late 19th century, several American inventors proposed special-purpose slide rules. One of them was James Hogg (1851–1930), an English mechanical engineer who came to the United States in 1880 and soon was overseer at the Globe Worsted Mill in Lawrence, Mass.
Description
By the late 19th century, several American inventors proposed special-purpose slide rules. One of them was James Hogg (1851–1930), an English mechanical engineer who came to the United States in 1880 and soon was overseer at the Globe Worsted Mill in Lawrence, Mass. During his time in Lawrence, Hogg devised this slide rule and arranged to have it manufactured by the Stanley Rule & Level Company of New Britain, Conn. He went on to patent a spindle for spinning machies (U.S. Patent 401,703) and feeding mechanisms for carding machines (U.S. Patents 562,610; 686,071; and 686,072).
This instrument is a wooden linear slide rule with a metal slide and metal edges on all four sides. The scales on the top of the base are lettered A, B, and C; the scales on the slide are lettered D and E; and the scales on the bottom of the base are lettered F, NUM, and LOG. The A and NUM scales range from 1 to 10, divided logarithmically. The B, C, D, and E scales range from 1 to 10 and then from 1 to 10 again, divided logarithmically. The F scale is divided like the B, C, D, and E scales, but runs in the opposite direction. The LOG scale is a scale of equal parts, ranging from 1 to 100 and divided in increments of one-half. The back of the slide is a twelve-inch scale divided to tenths of an inch and to eighths of an inch.
The back of the rule also has a twelve-inch scale divided to tenths of an inch on one edge and a twelve-inch scale divided to eighths of an inch on the other edge. In between are tables providing conversion factors from the volumes of geometric solids to cubic inches and feet; conversion factors from the volumes of geometric solids to the weights in pounds of various substances; the areas of polygons from 5 to 12 sides; the gauge points of a circle; and gauge points for pumping engines, to find the diameters of steam cylinders that will work pumps of specified diameter at 7 pounds per square inch. Compare to 1981.0934.01.
The back is marked: PAT. APPLIED FOR IMPROVED SLIDE RULE (/) ARRANGED & CONSTRUCTED BY (/) JAS. HOGG LAWRENCES MASS. U.S.A. (/) MANUFACTURED BY (/) STANLEY RULE & LEVEL CO. NEW BRITAIN, CONN. No patent has been found for the instrument.
Hogg moved from Lawrence in 1888 and subsequently worked for Stephen Sanford & Sons, Inc., in Amsterdam, N.Y., and the Bigelow Carpet Company in Lowell, Mass. An 1888 advertisement reported that the rule and instruction book sold together for $4.00. The instrument was still on sale in 1908, with instruction book, for a price of $3.50.
References: James Hogg, A Practical Course in Instruction with Hogg's Improved Slide-Rule in Arithmetic and Mensuration (Boston: Rand, Avery Co., 1887); "James Hogg," Transactions of the American Society of Mechanical Engineers 52 (1930): 77; "Hogg's Improved Slide Rule," Wade's Fibre & Fabric 7, no. 182 (August 25, 1888): 203, 209; "New Publications," Textile World Record 36 (1908): 631; Thomas Wyman, "Slide Rules of the Stanley Rule & Level Company and other American Makers," The Chronicle of the Early American Industries Association 54, no. 3 (2001): 114–117.
Location
Currently not on view
date made
1880-1888
maker
Stanley Rule and Level Company
ID Number
1991.0556.01
catalog number
1991.0556.01
accession number
1991.0556
This yew rule has straight brass ends and two slides, which fit between the three parts of the base.
Description
This yew rule has straight brass ends and two slides, which fit between the three parts of the base. On one side, the top scale on the base (labeled A), the two scales on the upper slide (labeled E), the first scale in the middle of the base (labeled D), and the two scales on the second scale (labeled B and C) are identical logarithmic scales that run from 1 to 10 twice in the length of the rule. The second scale in the middle runs from 1 to 100 and is labeled SEGT ST (segments standing). The lowest scale on the base is labeled SEGT LY (segments lying).
These scales are used with the slides to find the volume of the liquid in a cask that is not full, either when it is standing on its base or lying horizontally. The ImB and ImG points, for just over 2200 cubic inches in an imperial bushel and 277.42 cubic inches in an imperial gallon, are marked on the A scale. On the D scale, point 18.95 is marked IG for the diameter of a cylinder containing one imperial gallon; point 46.3 is marked MS, for the side of a square vessel that contains one solid bushel per inch of depth; and point 52.32 is marked MR, for the side of a square vessel that contains one malt bushel per inch of depth.
The reverse side of the rule has a scale on the base labeled A that runs logarithmically from 1 to 10. Both slides have identical scales (the one on the upper slide is labeled C) that run from over 80 (UNDER PROOF) down to 0 (PROOF) and then up to 70 (OVER PROOF). The middle of the base has a scale labeled B that runs logarithmically from 4 to 40 and a scale labeled C that runs logarithmically from 300 to 30. The bottom of the base has a scale, also labeled C, that runs logarithmically from 100 to 10. There is no indicator.
One edge of the instrument has a scale labeled SPHD and a scale labeled 2ND VARIETY. These scales are for determining the diameters of two different shapes of barrels. The other edge is marked: L. LUMLEY & CO LTD 1 AMERICA SQUARE LONDON. L. Lumley & Company, a distributor of packing cases and related materials for bottling, was in business in London from at least 1884 though 1929.
For slide rules with similar two-slide designs but different purposes, see MA.318478 and 1987.0693.01. For earlier gauger's rules, see MA.319510 and 1980.0588.04.
Reference: Ronald E. Manley, "Gauging," http://www.sliderules.info/a-to-z/gauging.htm.
Location
Currently not on view
date made
1884-1929
maker
L. Lumley & Company Limited
ID Number
MA.320637
catalog number
320637
accession number
242721
This large mahogany linear astronomical slide rule is covered with strips of German silver. There are two slides, each of which have scales on both sides. Each slide has a knob near one end for moving it; these may be unscrewed and attached on the reverse side.
Description
This large mahogany linear astronomical slide rule is covered with strips of German silver. There are two slides, each of which have scales on both sides. Each slide has a knob near one end for moving it; these may be unscrewed and attached on the reverse side. One slide is marked COLLIMATION on one side and AZIMUTH on the other. The other slide is marked LEVEL AZIMUTH on one side and REFRACTION on the other. The base has four identical, unlabeled logarithmic scales, each of which runs from 1 to 10 twice (with a bit more at each end).
On the center portion of the base, the instrument is marked Darling Brown & Sharpe Providence R.I. Darling, Brown & Sharpe did business under that name from 1866 to 1892. For additional company history, see 1977.0460.01. According to records of the United States Naval Observatory, this slide rule was purchased for $154.00 in December 1887. Few slide rules specifically for astronomy survive, so these large and expensive objects were probably not widely used. Compare to two late 19th-century rules held by the Powerhouse Museum, http://www.powerhousemuseum.com/collection/database/?irn=233017.
Reference: Ledger of Instruments Purchased by the U.S. Naval Observatory, ca. 1845–1906, United States Naval Observatory, Washington, D.C.
Location
Currently not on view
date made
1887
patentee
Darling, Samuel
maker
Brown & Sharpe Manufacturing Company
ID Number
1987.0693.01
catalog number
328994
accession number
1987.0693
This eight-inch wooden Mannheim linear slide rule is coated with white celluloid and has a brass indicator in the single chisel style. It has no endpieces. The top edge is beveled and has a scale of 20 centimeters, divided to millimeters.
Description
This eight-inch wooden Mannheim linear slide rule is coated with white celluloid and has a brass indicator in the single chisel style. It has no endpieces. The top edge is beveled and has a scale of 20 centimeters, divided to millimeters. A 20-centimeter scale, divided to millimeters, is on the front edge. A third 20-centimeter scale under the slide is numbered from 22 to 41.
The top of the base has a scale divided logarithmically from 1 to 10 twice. The bottom of the base has a scale divided logarithmically from 1 to 10. These are the usual A and D scales, although they are not lettered. One side of the slide has the same two scales (the usual B and C scales, although they are not lettered). The other side of the slide has a scale of tangents that runs from 0 to 45 degrees and is lettered T; a scale of equal parts that runs from 0 to 10 and divides every two centimeters into 50 increments; and a scale of sines that runs from 70 to 0 and is lettered S. Compare to MA.318474. There is a place on the back of the instrument for a table of physical constants, but there is no table.
The top of the base is marked: TAVERNIER-GRAVET. The bottom of the base is marked: RUE MAYET 19.PARIS. It is also marked there: KEUFFEL & ESSER Co NEW-YORK & CHICAGO. The back is marked: MÉDAILLES D'OR 1878 ET 1889.
The British engineer's rule was brought to France by Edme-François Jomard in 1815, and by around 1820 Paul-Etienne Lenoir was manufacturing them in Paris. Lenoir's firm was succeeded by Gravet-Lenoir and later Tavernier-Gravet. From about 1851, Tavernier-Gravet manufactured a slide rule on the design of Amédéé Mannheim; this is such a slide rule. It was made after Tavernier-Gravet was awarded gold medals at world's fairs held in Paris in 1878 and 1889.
Before Keuffel & Esser manufactured its own rules around the turn of the 20th century, the company sold slide rules from Tavernier-Gravet and from Dennert & Pape of Germany. (Additional company history is provided with MA.318477, MA.318478, and MA.326613.) Although the scales and indicator resemble the ten-inch model 479–2 (subsequently numbered 1746N and 1746), a rule of this length (scales about 8" long) is not listed in K&E catalogs. The ten-inch version with brass indicator cost $4.50 between 1883 and 1890. In 1892 the single-chisel indicator was replaced with a double-chisel indicator.
References: Florian Cajori, A History of the Logarithmic Slide Rule and Allied Instruments (New York: Engineering News Publishing Company, 1909), 55–58, 80–81; M. Jomard, "The Slide Rule in France—1815," trans. Francis Wells, Journal of the Oughtred Society 8, no. 2 (1999): 11–16; Catalogue of Keuffel & Esser, 17th ed. (New York, 1883), 93; Catalogue of Keuffel & Esser, 20th ed. (New York, 1887), 129; Catalogue of Keuffel & Esser, (New York, 1890), 131.
Location
Currently not on view
date made
1889-1892
maker
Tavernier-Gravet
ID Number
MA.318473
accession number
235479
catalog number
318473
This fourteen-inch boxwood Mannheim linear slide rule has a brass indicator in the single chisel style with an open interior. There are no endpieces. The top edge is beveled and has a scale of 35 centimeters, divided to millimeters.
Description
This fourteen-inch boxwood Mannheim linear slide rule has a brass indicator in the single chisel style with an open interior. There are no endpieces. The top edge is beveled and has a scale of 35 centimeters, divided to millimeters. The top of the base has a scale divided logarithmically from 1 to 10 twice, and the bottom of the base has a scale divided logarithmically from 1 to 10. These are the usual A and D scales, although they are not lettered.
One side of the slide has the same two scales (the usual B and C scales, although they are not lettered). The other side of the slide has a scale of tangents that runs from 0 to 45 degrees and is lettered T; a scale of equal parts that runs from 0 to 1,000; and a scale of sines that runs from 80 to 0 and is lettered S. Compare to MA.318474. A paper table glued to the back gives geometric formulae, physical constants for the latitude of Paris, units of measure in France and in England, rates of exchange for common currencies, specific gravities, expansion coefficients of various gases, temperatures of melting and boiling for various solids and liquids, and similar data.
The bottom of the base is marked: TAVERNIER – GRAVET; RUE MAET 19.PARIS. The back is marked: MÉDAILLES D'OR 1878 ET 1889. Keuffel & Esser donated this rule to the Smithsonian. As with MA.318473, K&E imported it to sell while the company developed the ability to manufacture its own slide rules. Also like MA.318473, the scales and indicator resemble the ten-inch model 479–2 (subsequently numbered 1746N and 1746), but a rule of this length (scales about 14" long) is not listed in K&E catalogs. The ten-inch version with brass indicator cost $4.50 between 1883 and 1890. In 1892, the single-chisel indicator was replaced with a double-chisel indicator.
References: Florian Cajori, A History of the Logarithmic Slide Rule and Allied Instruments (New York: Engineering News Publishing Company, 1909), 55–58, 80–81; Francis Wells and Tom Wyman, "La Règle à Calcul: Lenoir, Gravet-Lenoir, and Tavernier-Gravet Slide Rules," Journal of the Oughtred Society 11, no. 1 (2002): 23–27; Bob Otnes, "Keuffel & Esser — 1880 to 1899," Journal of the Oughtred Society 10, no. 1 (2001): 18–28; Catalogue of Keuffel & Esser, 17th ed. (New York, 1883), 93; Catalogue of Keuffel & Esser, 20th ed. (New York, 1887), 129; Catalogue of Keuffel & Esser, (New York, 1890), 131.
Location
Currently not on view
date made
1889-1892
maker
Tavernier-Gravet
ID Number
MA.318474
catalog number
318474
accession number
235479
This one-sided, ten-inch wooden rule has a layer of yellowed white celluloid on the front side. It has unlettered A and D scales on the base and B and C scales on one side of the slide. The other side of the slide has S, L, and T scales. The indicator is glass in a metal frame.
Description
This one-sided, ten-inch wooden rule has a layer of yellowed white celluloid on the front side. It has unlettered A and D scales on the base and B and C scales on one side of the slide. The other side of the slide has S, L, and T scales. The indicator is glass in a metal frame. The top edge is beveled and has a 25-centimeter scale, divided to millimeters. A second scale, 26 centimeters in length, is on the front edge. Underneath the slide is a third centimeter scale, numbered from 27 to 51.
The bottom of the base is marked in gold: A. W. FABER. Tables of equivalent measures and lists of constants (in German) are printed on paper glued to the back of the instrument. The rule is in a cardboard case covered with black leather, which is in excellent condition. The case is marked: Rechenstab (/) von (/) A. W. Faber. The back of the case is signed illegibly in pencil.
A. W. Faber began manufacturing wooden slide rules in 1882 and added celluloid facings in 1887. From about 1888 to 1900, the rules were often marked not only "A. W. FABER" but "Made in Germany." The metal indicator with a glass window was introduced in 1889. Although there is no model number on this rule, in the 1910s this combination of scales and indicator was sold as model 360. See MA.304722.02 for a later version of this rule, which mentions an 1899 patent and has a digit registering indicator introduced in 1905.
Reference: Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries, trans. Rodger Shepherd (Mendham, N.J.: Astragal Press, 2000), 54, 90; Trevor Catlow, "Suggestions for Dating pre-1920 Faber Castell Slide Rules," Journal of the Oughtred Society 18, no. 2 (2009): 46–53; "Time Line for A. W. Faber and Faber-Castell," http://sliderulemuseum.com/SR_Dates.htm#Faber.
Location
Currently not on view
date made
about 1890
maker
Faber, A. W.
ID Number
MA.314793
catalog number
314793
accession number
210147
This ten-inch mahogany rule is coated with white celluloid on the front and back and is held together with straight brass end pieces. Two screws are in one of the end pieces. The indicator is brass in the double chisel style.
Description
This ten-inch mahogany rule is coated with white celluloid on the front and back and is held together with straight brass end pieces. Two screws are in one of the end pieces. The indicator is brass in the double chisel style. On one side, the bottom of the base is marked: WM COX. PAT. OCT. 6. 1891. The right side of the top of the base and the slide are both marked: *. On the other side, the bottom of the base is marked: KEUFFEL & ESSER Co. NEW-YORK.
The scales are not labeled. On both sides, the top of the base has an A scale (divided logarithmically from 1 to 10 twice) and the bottom of the base has a D scale (divided logarithmically from 1 to 10 once). One side of the slide has B and C scales. (A B scale is equivalent to an A scale, and a C scale is equivalent to a D scale.) The other side of the slide has BI and CI scales (i.e., B-inverse and C-inverse).
British citizen William Cox received U.S. patent number 460,930 for a duplex "Engineer's Slide-Rule" with these scales on October 6, 1891, and immediately assigned the patent to the Keuffel & Esser Company of New York. This slide rule sold as K&E model 1744 from 1895 to 1900 and as model 4070 from 1901 to 1906. In the 1895 K&E Catalog, which includes the patent drawings in the illustration, the K&E mark is shown near the top of the base instead of near the bottom of the base. The mark is shown near the bottom of the base in the 1897 and 1899 catalogs. The shape of the end pieces was altered in 1901, and a second style of indicator, the glass clam shell, was added as model 4071. By 1909, K&E discontinued model 4070. Thus, this example likely dates to 1896–1900. It would have been partially made by Dennert & Pape in Germany and finished in the United States by K&E, which sold it in a case for $6.50.
K&E donated this slide rule to the Smithsonian in 1961. Compare to model 4071: MA.318475, MA.326613, and 1993.0482.01.
References: Catalogue of Keuffel & Esser Co., 26th ed. (New York, 1895), 186; Catalogue of Keuffel & Esser Co., 28th ed. (New York, 1897), 192; Catalogue of Keuffel & Esser Co., 29th ed. (New York, 1899), 193; Catalogue of Keuffel & Esser Co., 30th ed. (New York, 1900–1901), 296; Catalogue of Keuffel & Esser Co., 32th ed. (New York, 1906), 324; Clark McCoy, "Collection of Pages from K&E Catalogs for the Early 4071 Family of Slide Rules," http://www.mccoys-kecatalogs.com/KEModels/ke4071oldfamily.htm; Wayne E. Feely, "K & E Slide Rules," The Chronicle of the Early American Industries Association 49, no. 5 (June 1996): 50–52; Dieter von Jezierski, Slide Rules: A Journey Through Three Centuries, trans. Rodger Shepherd (Mendham, N.J.: Astragal Press, 2000), 71.
Location
Currently not on view
date made
1896-1900
maker
Keuffel & Esser Co.
ID Number
MA.318477
catalog number
318477
accession number
235479
This ten-inch wood slide rule is faced with white celluloid on both sides. The indentations on the metal end pieces face in, as was typical for Keuffel & Esser slide rules manufactured between 1901 and 1913; compare to MA.326613.
Description
This ten-inch wood slide rule is faced with white celluloid on both sides. The indentations on the metal end pieces face in, as was typical for Keuffel & Esser slide rules manufactured between 1901 and 1913; compare to MA.326613. The brass indicator is in the double chisel style (with an open interior), used from 1891 to about 1909. See also MA.318477 and 1977.0370.01. The edge of the indicator is marked: KEUFFEL & ESSER CO. (/) NEW-YORK.
The slide has two parts, which fit between the three parts of the base. On one side, the top of the base has an A scale; the top of the slide has B and C scales; the middle of the base has D and DF scales; the bottom of the slide has C and S scales; and the bottom of the base has an A scale. The bottom of the base is marked: KEUFFEL & ESSER Co NEW-YORK. On the left edge of the rule, the top and bottom of the base and the slide are all stamped: 5.
On the other side, the top of the base has an A scale; the top of the slide has BI and CI scales; the middle of the base has D and DF scales; the bottom of the slide has CIF, L, and T scales; and the bottom of the base has a D scale. On both sides, the DF scale is unlettered. The CIF scale is incorrectly lettered "CI." Unlike later slide rules, which start at pi, the folded scales on this rule (CF, CIF, and DF) start at the square root of 10 (approximately 3.16).
The bottom of the base on the back is marked in red: PAT. OCT. 6. 1891 & MAR. 21. 1899. The second patent date is in a different font and size than the first. The first patent refers to William Cox's invention of the duplex slide rule, which K&E used to launch its manufacture of American slide rules. William L. E. Keuffel, the company's head of manufacturing, received the second patent for the design of the dual slide seen in this rule.
K&E only used the dual slide on its Universal slide rule, suggesting the concept was not as useful as the company hoped. The dual slide also addressed a limitation of K&E dividing engines, which were only able to cut scales on the edges of rules. Once K&E improved its dividing engines, this solution was no longer necessary. The Universal slide rule sold as model 4090 from 1900 to 1905 and as the model 4090N from 1906 to 1911. From 1900 to 1902, it had a brass chisel indicator; from 1903 to 1905, it had a German silver chisel indicator; and from 1906 to 1911 it had a glass clam shell indicator. This example thus dates to 1900–1902. It sold for $20.00.
References: William Cox, "Engineer's Slide-Rule" (U.S. Patent 460,930 issued October 6, 1891); W. L. E. Keuffel, "Slide Rule" (U.S. Patent 621,348 issued March 21, 1899); Catalogue of Keuffel & Esser Co., 30th ed. (New York, 1900–1901), 297; Catalogue of Keuffel & Esser Co., 31st ed. (New York, 1903), 307; Bob Otnes and Bob DeCesaris, "The K&E Universal Slide Rule," Journal of the Oughtred Society 10, no. 2 (2001): 45–48; Bob Otnes, "The 31st (1903) and 32nd (1906) Editions of the K&E Catalogue," Journal of the Oughtred Society 11, no. 2 (2002): 24–32.
Location
Currently not on view
date made
1900-1902
maker
Keuffel & Esser Co.
ID Number
MA.318478
catalog number
318478
accession number
235479
This 20-inch mahogany linear slide rule is coated on the front and back with white celluloid; the edges are bare. The scales are labeled on the right end of each side. On both sides, the top of the base has an A scale, and the bottom of the base has a D scale.
Description
This 20-inch mahogany linear slide rule is coated on the front and back with white celluloid; the edges are bare. The scales are labeled on the right end of each side. On both sides, the top of the base has an A scale, and the bottom of the base has a D scale. On one side, the slide has B and C scales; on the other, the slide has BI and CI scales. The rule has two indicators: the original brass double-chisel style indicator, and the frameless glass with plastic edges that Keuffel & Esser adopted in 1915. According to the donor, the second indicator was acquired some years after the original slide rule.
The bottom of the base on one side and the chisel indicator on the other side are both marked: KEUFFEL & ESSER Co. NEW-YORK. The bottom of the base is also engraved: CHAS. C. BRUSH 1901. The symbol for pi has also been scratched on the D scale on that side. On the other side, the bottom of the base is marked: PAT. OCT. 6. 1891. One edge of the frameless indicator is marked: K&E.CO.N.Y. (/) PAT.8.17.15. For information on these patents, see MA.318477 and MA.318475.
The cardboard case is covered with brown morocco leather. It is marked: KEUFFEL & ESSER CO. (/) DUPLEX (/) SLIDE RULE. See the similar case for MA.326613.
According to the donor, the instrument was used by his father, Charles C. Brush (1880–1968), who graduated from high school in Philadelphia in 1898 and subsequently studied at the Franklin Institute. He received a certificate from the School of Naval Architecture there in 1904. The model 4078 is only listed in Keuffel & Esser catalogues for 1901 and 1903, priced at $16.50. The catalog evidence and the date on the slide rule make it reasonable to suppose that Brush acquired the slide rule in the course of his studies. Charles C. Brush was then associated with the Bureau of Lighthouses from 1917 to 1939. When the Lighthouse Service ended in 1939, he served as a marine engineer in the engineering department of the U.S. Coast Guard until his retirement in 1944.
References: Catalogue of Keuffel & Esser Co., 30th ed. (New York, 1900–1901), 296; Catalogue of Keuffel & Esser Co., 31st ed. (New York, 1903), 306; accession file.
Location
Currently not on view
date made
1901-1903
maker
Keuffel & Esser Co.
ID Number
1977.0370.01
accession number
1977.0370
catalog number
335926
This ten-inch duplex mahogany slide rule is coated with white celluloid on the front and back; the edges are bare.
Description
This ten-inch duplex mahogany slide rule is coated with white celluloid on the front and back; the edges are bare. Unlike earlier slide rules from the Keuffel & Esser Company, such as MA.318477, the end pieces are silver-colored metal (not brass) and the indented edges of the end pieces face in instead of out. The indicator is glass in a brass frame, which was called the "clam shell" style.
The scales are labeled. On both sides, the top of the base has an A scale and the bottom of the base has a D scale. The slide has B and C scales on one side and BI and CI scales on the other side. On one side, the bottom of the base is marked: KEUFFEL & ESSER Co.N.Y. It is also marked there: B.S.5470. On the other side, the bottom of the base is marked in red: PAT. OCT. 6. 1891. The bottom edge of the indicator is engraved: KEUFFEL & ESSER CO (/) NEW–YORK.
The instrument fits in a cardboard box covered with black morocco leather. The large part of the box is embossed: KEUFFEL & ESSER Co. (/) DUPLEX (/) SLIDE RULE. The U.S. National Bureau of Standards (now the National Institute of Standards and Technology) transferred this instrument to the Smithsonian in 1965 as excess property.
K&E sold this instrument as model 4071 from 1901 to 1917. By this time, K&E was manufacturing slide rules from start to finish at its factory in Hoboken, N.J. In 1913, the shape of the end pieces was changed to an "L," as with MA.318475. That instrument also has patent dates of 1900 and 1908 on it, suggesting that this slide rule dates from 1908 or earlier. The 1909 catalog describes the 1908 patent as "pending." Model 4071 initially sold for $8.00 and was reduced to $7.00 in 1906 and to $5.00 in 1909.
References: William Cox, "Engineer's Slide-Rule" (U.S. Patent 460,930 issued October 6, 1891); Clark McCoy, "Collection of Pages from K&E Catalogs for the Early 4071 Family of Slide Rules," http://www.mccoys-kecatalogs.com/KEModels/ke4071oldfamily.htm; Catalogue of Keuffel & Esser Co., 30th ed. (New York, 1900–1901), 296; Catalogue of Keuffel & Esser Co., 31st ed. (New York, 1903), 306; Catalogue of Keuffel & Esser Co., 32th ed. (New York, 1906), 325; Catalogue of Keuffel & Esser Co., 33rd ed. (New York, 1909), 312; Catalogue of Keuffel & Esser Co., 34th ed. (New York, 1913), 303.
Location
Currently not on view
date made
1901-1908
maker
Keuffel & Esser Co.
ID Number
MA.326613
catalog number
326613
accession number
261654
This 22-inch, two-sided wooden slide rule has scales that are printed on paper but not engine-divided. On the front of the base, logarithmic scales are labeled B and C on the left and D and D on the right.
Description
This 22-inch, two-sided wooden slide rule has scales that are printed on paper but not engine-divided. On the front of the base, logarithmic scales are labeled B and C on the left and D and D on the right. The C scale is the inverse of the B scale and is also labeled RECIPROCALS. The first D scale runs from 1 to 3.16, and the second D scale runs from 3.16 to 10. These scales are labeled ROOTS.
Four identical scales are on the slide, all logarithmically divided from 1 to 10 and labeled A. Two of the scales are at the left end of the slide, and two are at the right end of the slide. These scales are also identical to the B scale. Written in pencil on the back of the slide and underneath the slide is the number 1103. The bottom of the base is marked: Patented July 2, 1901.
The back of the base has scales divided logarithmically from 1 to 10 and from 3.16 to 10 to 3.16. These scales are both labeled F at both ends. The slide also has scales divided logarithmically from 1 to 10 and from 3.16 to 10 to 3.16. These scales are both labeled E at both ends. Faded red numbers from 1 to 4 also appear on all four scales. Written in pencil on the back of the slide and underneath the slide is: 1102. The bottom of the base is marked: Patented July 2, 1901.
The top edge of the rule is marked: THE ENGINEERS (/) SLIDE RULE. It is also marked: From E. M. Scofield, Bridge Engineer. (/) Sta. A, – Youngstown, – Ohio. (/) Rule sent prepaid on receipt of price. (/) Factory, – Youngstown, Ohio. The paper pasted on this edge also has the formula ex/f, a description of how to solve this formula with the instrument, and tables of equivalents. The bottom edge of the rule gives seventeen more formulas and instructions. It is marked: DIRECTIONS FOR SCALES A • B • C & D (/) FOR "Op." READ "OPPOSITE" (/) FOR "—" READ "ON SCALE" (/) FOR "Ans." READ "FIND ANSWER" (/) FOR LAST SIX PROBLEMS REVERSE SLIDE.
Edson Mason Scofield (1867–1939) developed this rule in 1891 while he worked for Edwin Thacher (inventor of the cylindrical slide rule bearing his name; see, for example, MA.312866). Thacher applied for a patent on the design in 1900 and assigned a half-interest to Scofield when the patent was issued in 1901. According to the instrument, Scofield may have distributed the rule himself.
It was also sold by Eugene Dietzgen Company of Chicago from about 1901 through at least 1931. The price for model 1787 ranged from $5.00 to $7.00. By 1926 Dietzgen marked the rule with its company name. Meanwhile, Scofield went on to become president and chief engineer of the National Bridge Company of Pittsburgh in 1901. From 1903 he and his brother, Glenn M. Scofield, operated the Scofield Engineering Company in Philadelphia, New York City, and Los Angeles. This example belonged to Robert A. Cummings, a civil engineer who was the father of the donor. Compare to MA.333710.
References: Edwin Thacher, "Slide Rule" (U.S. Patent 677,817 issued July 2, 1901); Catalogue & Price List of Eugene Dietzgen Co., 7th ed. (Chicago, 1904), 173; Catalog of Eugene Dietzgen Co., 12th ed. (Chicago, 1926), 177; Conrad Schure, "The Scofield-Thacher Slide Rule," Journal of the Oughtred Society 3, no. 1 (1994): 20–25; Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 161.
Location
Currently not on view
date made
1901-1926
maker
Scofield, E. M.
ID Number
MA.325990
catalog number
325990
accession number
258733
The scales on this 22-inch, two-sided wooden slide rule are printed on paper. The front has two scales on the left end of the base labeled B and C and two scales labeled A on the left end of the slide. These scales run half the length of the instrument.
Description
The scales on this 22-inch, two-sided wooden slide rule are printed on paper. The front has two scales on the left end of the base labeled B and C and two scales labeled A on the left end of the slide. These scales run half the length of the instrument. The B and two A scales are identical, divided logarithmically from left to right and running from 1 to 10. The C scale is divided logarithmically from right to left and runs from 10 to 1. It is labeled RECIPROCALS.
The right end of the base has two D scales, both labeled ROOTS, with two additional A scales on the right end of the slide. The A scales are divided logarithmically from left to right and run from 1 to 10. The top D scale runs from 1 to 3.16 and shows square roots of the numbers on the A scale below it. The bottom D scale runs from 3.16 to 10 and shows square roots of the numbers on the A scale above it, between 10 and 100. Written in pencil on the back of the slide and underneath the slide is the number 1096.
The back of the rule contains two scales on the base labeled F and two scales on the slide labeled E. The top F scale runs the length of the scale and is divided logarithmically from 1 to 10. The sections between 1 and 2, between 2 and 3, between 3 and 4, and between 4 and 5 are subdivided. The lower F scale is similarly divided, but starts from the center of the rule (running from the square root of 10, or 3.16, to 10 and then from 1 to the square root of 10). The E scales are identical to the adjacent F scales. Written in pencil on the back of the slide and underneath the slide is the number 1097.
The bottom of the base on both sides is marked: Patented July 2, 1901. The top edge of the rule is marked: THE ENGINEERS (/) SLIDE RULE. It is also marked: From E. M. Scofield, Bridge Engineer. (/) Sta. A, – Youngstown, – Ohio. (/) Rule sent prepaid on receipt of price. (/) Factory, – Youngstown, Ohio. The paper pasted on this edge also has the formula ex/f, a description of how to solve this formula with the instrument, and tables of equivalents. The bottom edge of the rule gives seventeen more formulas and instructions. It is marked: DIRECTIONS FOR SCALES A • B • C & D (/) FOR "Op." READ "OPPOSITE" (/) FOR "—" READ "ON SCALE" (/) FOR "Ans." READ "FIND ANSWER" (/) FOR LAST SIX PROBLEMS REVERSE SLIDE.
Edson Mason Scofield (1867–1939) developed this rule in 1891, while he worked for Edwin Thacher (inventor of the cylindrical slide rule bearing his name; see, for example, MA.312866). Thacher applied for a patent on the design in 1900 and assigned a half-interest to Scofield when the patent was issued in 1901. According to the instrument, Scofield may have distributed the rule himself. It was also sold by Eugene Dietzgen Company of Chicago from about 1901 through at least 1931. The price for model 1787 ranged from $5.00 to $7.00. By 1926, Dietzgen marked the rule with its company name. This instrument is identical to MA.325990.
John N. Welsh (1904–1999), the donor of this slide rule, was a chemical engineer who obtained his B.S. from the Carnegie Institute of Technology in 1925. He was associated with Hall Laboratories, Inc. of Pittsburgh (later CALGON) from 1939 through at least 1968. By 1972, when this slide rule was briefly placed on exhibit, Welsh was living in Florida.
References: Edwin Thacher, "Slide Rule" (U.S. Patent 677,817 issued July 2, 1901); Catalogue & Price List of Eugene Dietzgen Co., 7th ed. (Chicago, 1904), 173; Catalog of Eugene Dietzgen Co., 12th ed. (Chicago, 1926), 177; Conrad Schure, "The Scofield-Thacher Slide Rule," Journal of the Oughtred Society 3, no. 1 (1994): 20–25; Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 161; Who's Who in Engineering (New York and West Palm Beach: Lewis Historical Publishing Co., 1964), 1996.
Location
Currently not on view
date made
1901-1926
maker
Scofield, E. M.
ID Number
MA.333710
catalog number
333710
accession number
300658
Edward Wager-Smith (1872–1920), a native of New Jersey, graduated from the Spring Garden Institute in Philadelphia in 1889 and in 1893 gained employment as a draftsman for Merritt & Company, a structural steel firm in Philadelphia.
Description
Edward Wager-Smith (1872–1920), a native of New Jersey, graduated from the Spring Garden Institute in Philadelphia in 1889 and in 1893 gained employment as a draftsman for Merritt & Company, a structural steel firm in Philadelphia. As he rose to the position of structural engineer by 1910, he invented the Wager Timber Scale and the Merritt Beam Scale (1987.0108.02). This rule assisted architects and construction workers with computing the strength of wooden beams. It has 11 scales: A, thickness in inches; B, depth in inches; C, spacing in feet; D, span in feet; E, fibre [sic] stress in pounds per square inch; F, load in pounds per square foot; G, type of wood; H, depth in inches; I, method of loading; J, span in feet; and K, fibre stress in pounds per square inch. Scales A-B-C-D-E-F are meant to be used together, as are scales A-B-I-J-K-L and scales G-H-I-J.
The back of the instrument gives government recommendations and regulations for safe stresses on wooden beams and a moisture classification chart by A. L. Johnson, "Economical Designing of Timber Trestle Bridges," U.S. Department of Agriculture Division of Forestry Bulletin No. 12 (Washington, D.C.: Government Printing Office, 1902), 11–12. The instrument fits in an orange paper envelope, which has instructions on its flap.
This rule was distributed by the John Howard Herrick Company of Baltimore, a dealer of hardware and building materials. A photographer by avocation, Wager-Smith also designed the Wager Exposure Scale (patented in 1901—see 1993.0386.01) for correctly timing photographic exposures and the Wager Definition Scale (copyright 1905—see 1993.0386.02 and PG*4750) for determining the longest exposure allowable to produce clearly defined images of moving objects.
The instrument is marked on the front and on the envelope: The Wager Timber Scale (/) FOR COMPUTING THE STRENGTH OF WOODEN BEAMS. It is also marked in both places: THE JOHN HOWARD HERRICK CO. (/) BALTIMORE, MD., U.S.A. It is also marked in both places: PRICE ONE DOLLAR. It is also marked on the front: PAT. JULY 1ST, 1902. This refers to a patent for a "slide-scale" resembling the Merritt Beam Scale and issued on that date to James S. Merritt of Philadelphia. The Wager Timber Scale was advertised for sale from Philadelphia by January 1905 and was mentioned in a textbook as late as 1921.
References: "Wager-Smith, E.," National Cyclopaedia of American Biography (New York: James T. White, 1926), xix:136–137; "Notes and Comment," The New Photo-Miniature 6, no. 3 (1904): 558; James S. Merritt, "Slide Scale" (U.S. Patent 703,437 issued July 1, 1902); "The Wager Timber Scale," Municipal Journal and Engineer 18, no. 1 (1905): 48; "Municipal and Technical Literature: New Publications," Municipal Engineering 29, no. 6 (1905): 448–449; Ernst McCullough, Practical Structural Design (New York: U.P.C. Co., 1921), 81.
Location
Currently not on view
date made
1902-1921
maker
Wager-Smith, Edward
ID Number
1987.0108.01
accession number
1987.0108
catalog number
1987.0108.01
This paper linear slide rule was designed to assist architects and construction workers with computing the strength of steel beams.
Description
This paper linear slide rule was designed to assist architects and construction workers with computing the strength of steel beams. There are seven scales: A, safe load in pounds per square foot; B, section of beams; C, spacing of beams in feet; D, span in feet; E, total safe load in net tons; F, manner of loading; G, span in feet. Scales A-B-C-D are meant to be used together, as are scales E-B-F-G. The back of the instrument gives instructions. The instrument fits in an orange paper envelope.
The front of the instrument and the envelope are marked: The Merritt Beam Scale (/) FOR COMPUTING THE STRENGTH OF STEEL BEAMS. They also are both marked: THE JOHN HOWARD HERRICK CO. (/) BALTIMORE, MD., U.S.A. and PRICE ONE DOLLAR. The front of the instrument also is marked: Copyright (/) 1899 (/) by (/) James S. Merritt (/) M.E. and PAT. JULY 1ST, 1902. This last mark refers to a patent for a "slide-scale" taken out on that date by the mechanical engineer James S. Merritt of Philadelphia. The Merritt Beam Scale was mentioned in a textbook as late as 1921.
Although the instrument is named for Merritt, its invention is credited to Edward Wager-Smith (1872–1920), who worked for Merritt & Co. of Philadelphia from 1893 to 1910. See also his Wager Timber Scale (1987.0108.01).
References: James S. Merritt, "Slide Scale" (U.S. Patent 703,437 issued July 1, 1902); "Wager-Smith, E.," National Cyclopaedia of American Biography (New York: James T. White, 1926), xix:136–137; Ernst McCullough, Practical Structural Design (New York: U.P.C. Co., 1921), 81.
Location
Currently not on view
date made
1902-1921
maker
Wager-Smith, Edward
ID Number
1987.0108.02
accession number
1987.0108
catalog number
1987.0108.02
This wooden ten-inch Mannheim slide rule is faced with white celluloid. The top edge is beveled and has a scale of inches divided to sixteenths of an inch. The bottom edge is flat and has a scale of centimeters divided to millimeters.
Description
This wooden ten-inch Mannheim slide rule is faced with white celluloid. The top edge is beveled and has a scale of inches divided to sixteenths of an inch. The bottom edge is flat and has a scale of centimeters divided to millimeters. The base has A and D scales, with B and C scales on one side of the slide and S, L, and T scales on the other side of the slide. The L scale is not lettered. The base underneath the slide is marked: EUGENE DIETZGEN CO. CHICAGO–NEW YORK (/) W. F. M. It is also marked: PAT. JUNE 28 1898. The indicator is glass in a metal frame. A paper glued to the back of the rule gives the properties of various substances and equivalents of various weights and measures. Carved into the back is: W.F.M. 1907.
The base of the rule is cut lengthwise into two sections that are joined together by invisible springs. This was intended to create more uniform resistance to the motion of the rule (even if it is fully extended) and to make it possible to straighten the parts of the rule by scraping, should it become warped. A cardboard box covered with burgundy leather is marked: The Mack Improved Slide Rule (/) NO. 1765 (/) EUGENE DIETZGEN CO. (/) CHICAGO. NEW YORK.
This rule is named for John Givan Davis Mack (1867–1924), an early member of the engineering faculty at the University of Wisconsin who taught from 1893 to 1915. On June 28, 1898, he received U.S. Patent 606388 for dividing the base of a slide rule and rejoining the pieces with springs. He assigned the patent to the Eugene Dietzgen Company of Chicago, which first sold a slide rule built on Mack's patent in 1898 and offered this version from 1902 to 1912 for $4.50.
The carved initials are those of the owner, the spectroscopist William F. Meggers (1888–1966), who was long associated with the U.S. National Bureau of Standards. He received his B.A. in physics from Ripon College in 1910, his M.A. in physics from the University of Wisconsin in 1916, and his Ph.D. in physics, mathematics, and astronomy from Johns Hopkins University in 1917. It seems likely that he acquired this rule as a student. For a less precise slide rule associated with Meggers, see 293320.2820. For later slide rule instructions distributed by Dietzgen, see 1981.0933.07.
References: Catalogue & Price List of Eugene Dietzgen Co., 7th ed. (Chicago, 1904), 171; Rodger Shepherd, "Some Distinctive Features of Dietzgen Slide Rules," Journal of the Oughtred Society 5, no. 2 (1996): 42–45; Peter M. Hopp, Slide Rules: Their History, Models, and Makers (Mendham, N.J.: Astragal Press, 1999), 159–160, 276; J. G. D. Mack Papers, University of Wisconsin Archives: U. S. Patent 606388.
Location
Currently not on view
date made
1907
maker
Eugene Dietzgen Company
ID Number
MA.335270
catalog number
335270
accession number
314637
This linear slide rule reflects changes that occurred in the materials of American manufacturing in the late 19th and early 20th centuries. The instrument itself has a pyroxylin (celluloid) envelope with a paper slide. There is no indicator.
Description
This linear slide rule reflects changes that occurred in the materials of American manufacturing in the late 19th and early 20th centuries. The instrument itself has a pyroxylin (celluloid) envelope with a paper slide. There is no indicator. It was designed for use in computing the properties of belting used in industrial processes. At that time, such belting was typically made from one of three materials: canvas saturated with a liquid, leather, or rubber. The Boston chemical firm of J. A. and W. Bird and Company developed a new material that they called "Bird's Bull's Eye Belting," which consisted of canvas plies stitched together, with a gum base pressed around each cotton fiber. The maker claimed that this belting did not dry out (as the usual form of canvas belting did), resisted damage from fumes or humidity, and maintained its tension.
This instrument has two sides. The front, or "Computer for Belting," allows the user to find the revolutions per minute of a pulley, the speed of the belt in feet per minute, and the proper belt width for the horsepower, given the diameter of the matched pulley and its revolutions per minute. The back, or "Computer for Shafting" side, allows calculation of the horsepower a shaft can communicate, given the shaft's diameter and revolutions per minute. The calculation is made using Thurston's formula, which states that the horsepower equals the cube of the shaft diameter times the number of times it revolves per minute divided by a constant dependent on the nature of the shaft.
The instrument is marked on the front: COPYRIGHTED 1908 (/) BY J.A. & W. BIRD & CO. (/) ALL RIGHTS RESERVED BOSTON, MASS. On the back, it is marked near the left center in very small letters: PAT. JUNE 6, 1905. (/) THE WHITEHEAD & HOAG CO. NEWARK, N.J. Whitehead & Hoag manufactured a variety of plastic products including slide rules; see 1984.1080.01, 1987.0221.02, and 1988.0350.01 (which is also a belting computer).
References: Richard E. Roehm, "Process of Printing upon Pyroxylin Materials" (U.S. Patent 791,503 issued June 6, 1905); J. A. & W. Bird & Co., Belt Talks (Boston, 1909), 18. According to this publication, customers could receive one rule by sending 10 cents in stamps. A second rule cost 25 cents.
Location
Currently not on view
date made
after 1908
maker
Whitehead & Hoag Company
ID Number
1988.0323.02
accession number
1988.0323
catalog number
1988.0323.02
In the late 19th and early 20th centuries, several American inventors strove to produce inexpensive slide rules. One of them was George Washington Richardson (about 1866–1940), who was born in the United States of British parents. He served as a chief electrician in the U.S.
Description
In the late 19th and early 20th centuries, several American inventors strove to produce inexpensive slide rules. One of them was George Washington Richardson (about 1866–1940), who was born in the United States of British parents. He served as a chief electrician in the U.S. Navy. Census records indicate that by 1910, he was living in Chicago with his wife, young son, and wife's parents and working as an engineer in a Chicago public school. Seeking to better himself, Richardson enrolled in an International Correspondence Schools (I.C.S.) course in electrical engineering in 1901, receiving his diploma in 1904. He copyrighted his first slide rule in 1903, began selling it in 1907, and advertised it in Popular Mechanics by 1909. Working with mechanical engineer John Jesse Clark, the dean of the faculty at I.C.S., he developed a range of slide rules and took out patents in 1911, 1912, and 1918. By 1920, Richardson sold his business to the Gilson Slide Rule Company, purchased an expensive automobile, and retired. He remained in Chicago until his death.
This roughly made 11-inch simplex slide rule has an aluminum frame that holds two pieces of a white celluloid base and a white celluloid slide. The top of the base has an A scale, the bottom has a D scale, and the slide has B and C scales. The A and B scales are logarithmically divided from 1 to 100, and the C and D scales are logarithmically divided from 1 to 10. Various letters are revealed in keyholes in the upper left and lower right corners of the base. These letters correspond to a conversions of units table on paper glued to the back of the rule. An aluminum indicator has a plastic window and is marked: PAT.PEND.
The top of the base is marked: GEO. W. RICHARDSON'S DIRECT READING SLIDE RULE. The bottom of the base is marked: ADDRESS : 4212, 24TH PLACE, CHICAGO, ILL. The back has instructions and is marked: Copyright 1903 By George W. Richardson. The slide rule sold with an instruction booklet for $1.50 in 1909, and with a modified indicator for $2.00 in 1910.
References: Mike Konchak, "Geo. W. Richardson Rule Works," http://sliderulemuseum.com/Richardson.htm; Bruce E. Babcock, "George Washington Richardson's Direct Reading Slide Rules," Journal of the Oughtred Society 1, no. 1 (1992): 9–13; George W. Richardson, "New Slide Rule," Popular Mechanics 12 (October 1909): advertising section, 122; "Slide Rule for Mathematical Calculations," Popular Electricity and the World's Advance 2, no. 11 (March 1910): 774; George W. Richardson, "A Direct Reading [Slide] Rule," Modern Machinery 24, no. 12 (April 1910): 330–331; "Direct Readings from a Slide Rule," Practical Engineer 14, no. 8 (August 1910): 502; "Circles and Squares: Use of the Double Scale for Boiler Problems" Practical Engineer 14, no. 11 (November 1910): 701; George W. Richardson, "Slide Rule" (U.S. Patent 982,876 issued January 31, 1911), "Slide Rule" (U.S. Patent 1,021,484 issued March 26, 1912), and "Slide Rule" (U.S. Patent 1,260,454 issued March 26, 1918). On Richardson and Gilson, see also MA.316707.
Location
Currently not on view
date made
ca 1909
maker
George W. Richardson
ID Number
2009.0038.02
accession number
2009.0038
catalog number
2009.0038.02
This five-inch, one-sided cardboard linear slide rule has a metal cursor in the double-chisel style. (Compare to MA.318477 and 1977.0370.01.) There are A and D scales on the base and B and C scales on the slide. The A and B scales are divided logarithmically from 1 to 10 twice.
Description
This five-inch, one-sided cardboard linear slide rule has a metal cursor in the double-chisel style. (Compare to MA.318477 and 1977.0370.01.) There are A and D scales on the base and B and C scales on the slide. The A and B scales are divided logarithmically from 1 to 10 twice. The C and D scales are divided logarithmically from 1 to 10 once. A figure holding a club is shown in the lower left corner. A dark brown case of coated paper is included.
The figure on the slide rule was used by Gebr. Wichmann (Wichmann Brothers) in Berlin, a company founded in 1873. In materials, size, and scales, this instrument closely resembles model 466, shown in the 1910 catalog. However, the illustration in the catalog indicates that the maker's name, place of manufacture, model number, and price are printed on the front of the rule. This instrument does not have these marks, so it may have been made before 1910. The No. 466 slide rule sold for 0.75 marks and was one of the least expensive slide rules listed in the catalog. (Only model 469, with a C scale that began at pi, sold for the same price.)
This instrument is signed on the back: W. F. Meggers. William F. Meggers (1888–1966) was a spectroscopist long associated with the U.S. National Bureau of Standards. He received his B.A. in physics from Ripon College in 1910, his M.A. in physics from the University of Wisconsin in 1916, and his Ph.D. in physics, mathematics, and astronomy from Johns Hopkins University in 1917. If he used this rule, it seems likely that he acquired it as a student. For a slide rule apparently acquired by Meggers in 1907 that was considerably more precise and more costly, see MA.335270.
References: Gebr. Wichmann, Anleitung zum Gebrauch des Rechenstabes (Berlin, 1910), 21; "Dr. Meggers Dies at 78," The NBS Standard 11, no. 9 (December 1966): 2–3.
Location
Currently not on view
date made
before 1910
maker
Gebr. Wichmann
ID Number
MA.293320.2820
accession number
293320
catalog number
293320.2820

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