Merritt Beam Scale Slide Rule

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 Ernest 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
Object Name
slide rule
date made
1902-1921
maker
Wager-Smith, Ernest
Physical Description
paper (overall material)
metal (part material)
Measurements
overall: .3 cm x 24.8 cm x 10.2 cm; 1/8 in x 9 3/4 in x 4 1/32 in
place made
United States: Pennsylvania, Philadelphia
ID Number
1987.0108.02
accession number
1987.0108
catalog number
1987.0108.02
subject
Science & Mathematics
Mathematics
Rule, Calculating
Engineering, Building, and Architecture
Slide Rules
Carpentry
See more items in
Medicine and Science: Mathematics
Slide Rules
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Transfer from Smithsonian Institution Libraries
Additional Media

Visitor Comments

Add a comment about this object

Submit a comment or ask a question about this object using the form below. Submissions are moderated and may receive a curator response. Please note that we cannot evaluate or appraise your personal artifacts. For other questions or general inquiries please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Image CAPTCHA
Enter the characters shown in the image.