Engineering, Building, and Architecture

Not many museums collect houses. The National Museum of American History has four, as well as two outbuildings, 11 rooms, an elevator, many building components, and some architectural elements from the White House. Drafting manuals are supplemented by many prints of buildings and other architectural subjects. The breadth of the museum's collections adds some surprising objects to these holdings, such as fans, purses, handkerchiefs, T-shirts, and other objects bearing images of buildings.

The engineering artifacts document the history of civil and mechanical engineering in the United States. So far, the Museum has declined to collect dams, skyscrapers, and bridges, but these and other important engineering achievements are preserved through blueprints, drawings, models, photographs, sketches, paintings, technical reports, and field notes.

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
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
Frank J. Thomas (1924–1976), a construction engineer from Topeka, Kan., invented the "Gradeulator" in the early 1970s.
Description
Frank J. Thomas (1924–1976), a construction engineer from Topeka, Kan., invented the "Gradeulator" in the early 1970s. This circular slide rule was used to convert survey rod readings to sea level elevations, to determine the quantities of cut and fill required for earthwork, and to establish elevations for site grading and pavements.
The instrument has a square white plastic base with rounded corners. The base is covered with white cardboard that is marked with a circle divided into 100 equal parts, with each part divided into tenths. Four paper discs, each backed with metal, rest on the base. Each disc is divided along the edge into 100 equal parts, 50 for "cut" and 50 for "fill," and has three rings of numbers for 100-, 50-, and 25-foot grids. The second-largest disc is turned upsidedown and has ten square notches along its edge. The smallest disc has paper marked with scales on both sides of the metal, with the "cut" sections outlined in red ink. The instrument is held together with a metal screw and wing nut.
A clear plastic pointer also pivots at the screw. A piece of clear plastic screwed to the right corner of the base holds the rim of the three largest discs. The inside of the smallest disc is marked: GRADEULATOR (/) INSTRUCTIONS COPYRIGHT © 1973 by FRANK J. THOMAS. The base is marked: GRADEULATOR; PATENT PENDING Frank J. Thomas serial no. 5-73; LEGEND (/) BASE = Rod Reading (/) DISC #1 = SEA LEVEL, 0–100 ft. (/) DISC #2 (Notched) = SEA LEVEL, hundreds (/) DISC #3 = SEA LEVEL, thousands (/) DISC #4 = DEPTH cut or fill, and QUANTITY per grid.
According to donor Rita Thomas Dukes, Thomas handmade and sold these instruments from his garage. The name "Gradeulator" was trademarked from November 11, 1975, to April 6, 1982 (serial no. 73013213, registration no. 1024537). In 1973, Thomas applied for a patent, which was issued in 1976.
Reference: Frank J. Thomas, "Rotary Slide Rule for Topographic Calculations" (U.S. Patent 3,937,930 issued February 10, 1976).
Location
Currently not on view
date made
1973-1982
maker
Thomas, Frank J.
ID Number
1990.0509.01
accession number
1990.0509
catalog number
1990.0509.01

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