| dc.contributor.institution | Colorado School of Mines. Information & Technology Solutions |
| dc.date | 2018 |
| dc.date.accessioned | 2018-08-30T20:59:35Z |
| dc.date.available | 2018-08-30T20:59:35Z |
| dc.description | Date of manufacture: early 20th century. |
| dc.description.abstract | Invented by Edwin Thacher, an American bridge engineer. Patented in 1881, production of this 20-scale cylindrical slide rule was assumed by Keuffel and Esser Co. of New York by 1897. This unit dates to approximately 1920, serial #3499. The 20 scales provide an effective length of 30 feet with an accuracy of 4 to 5 digits. Scales for square roots are also included. |
| dc.format.medium | born digital |
| dc.format.medium | digital photographs |
| dc.identifier.uri | https://hdl.handle.net/11124/172490 |
| dc.publisher | Colorado School of Mines. Arthur Lakes Library |
| dc.relation.ispartof | Mines Techology Museum |
| dc.subject.lcsh | Computers |
| dc.title | Thacher's calculating instrument |
| dc.type | Image |
