Mathematical Charts and TablesConversion Tables
As has been suggested already, instructive mathematical charts introduced unfamiliar units of measure. A number of handy tables also were produced to assist in conversions. Perhaps the earliest such chart in the collections dates from about 1814, and is designed to convert from units divisible by twelfths to decimal units. The size of conversion factor and the way the numbers are written suggest that it was made to convert from Massachusetts pounds and shillings to U.S. currency. By the mid-20th century, the dollar prevailed throughout the United States, and Americans were more concerned with understanding foreign currencies when they traveled abroad. Toward that end, some purchased a slide chart called the UNICON, which allowed them to convert between dollars and numerous foreign currencies when they knew the exchange rate.
Engineers have long needed to perform conversions as part of their work. In the first half of the 20th century, manufacturers sometimes distributed small advertising cards that listed decimal equivalents of parts of an inch. Larger tables might list a large number of useful conversion factors. New efforts to introduce metric weights and measures in the United States in the 1970s led to the distribution of a range of cards and slide charts that eased conversions. These were distributed by organizations ranging from the federal government to a manufacturer of outdoor clothing and camping supplies to a producer of food emulsifiers and flavorings.
"Mathematical Charts and Tables - Conversion Tables" showing 1 items.
- Companies seeking to provide customers with advertisements they might consult repeatedly sometimes distributed convenient mathematical tables. This is an example of one of these. The small white plastic card has figures printed in blue. The table gives decimal equivalents of parts of an inch ranging from 1/64” to 1” by sixty-fourth inch increments.
- The other side of the card has a small drawing that shows the wooden building occupied by Brown & Sharpe Manufacturing Company of Providence, Rhode Island, in 1848. It also shows the plant at the time the table was distributed, when it occupied 33 acres.
- A mark on the back of the table reads: FORM 93 M.M.T. 7-43:100. Another mark reads: PRINTED IN U. S. A. This mark suggests that the card dates from 1943.
- This table was found in the collections of what was then the Division of Work and Industry at the National Museum of American History.
- Compare 1988.3078.02.
- Currently not on view
- date made
- Brown & Sharpe Manufacturing Company
- ID Number
- catalog number
- nonaccession number
- Data Source
- National Museum of American History, Kenneth E. Behring Center