Artifact Details

Title

E. A. Sperry's Calculator

Catalog Number

XB97.80

Type

Physical object

Date

1911 (patented)

Manufacturer

Keuffel & Esser Company

Place Manufactured

U.S.

Identifying Numbers

Other number PAT. DEC. 26,11
Serial number S650

Dimensions

5/8 x 2 1/8 x 2 5/8 in.

Description

Calculator consists of circular number wheel with two adjustable thumb wheels at top center of device. Lower (larger) wheel rotates the dial itself; top (smaller) wheel turns indicator needle. Center of dial reads: "Pat. Dec. 26, 11" (December 26, 1911?). Smudge on outside edge near wheels on top and small amount of rust on bottom edge near attached loop.

Category

Analog computer

Collection Title

Gwen Bell artifact and book collection

Series Title

Pre-computing artifacts

Credit

Courtesy Gwen and Gordon Bell

Lot Number

XB97.80