Slide Chart, Heat Gain Calculator

This orange and black paper device has a set of tables printed on both sides of a piece of cardboard that slides between two other pieces of cardboard that are riveted together. The whole thing fits in a cardboard envelope. The tables are used to calculate the total heat gain from light shining through windows and other glass in a building. The instrument was distributed by Libbey Owens Ford Company, a glass firm in Ohio.
A mark on the envelope and the object reads: HEAT GAIN CALCULATOR; A paper sticker attached to the envelope reads: Display Copy Only (/) Please do not remove. A mark on the back of the instrument in the bottom right corner reads: ... 1975, PERRYGRAF Div., Nashua LA. CA 90064 Printed in U.S.A. A mark on the front left corner reads: LOF (/) GLASS (/) 811 MADISON AVENUE (/) TOLEDO, OHIO 43695. A mark on the front of the instrument reads: LIBBEY (/) OWENS (/) FORD (/) COMPANY.
Currently not on view
date made
Perrygraf Division, Nashua
place made
United States: California, Los Angeles
Physical Description
paper (overall material)
metal (overall material)
overall: .3 cm x 28.5 cm x 18 cm; 1/8 in x 11 7/32 in x 7 3/32 in
ID Number
nonaccession number
catalog number
Credit Line
Gift of Jack Warner
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Mathematical Charts and Tables
Data Source
National Museum of American History, Kenneth E. Behring Center


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