Object Record
Keuffel & Esser Thacher's (Cylindrical) Calculating Instrument
Keuffel & Esser Thacher’s (Cylindrical) Calculating Instrument
Keuffel & Esser Thacher’s (Cylindrical) Calculating Instrument end
| Catalog Number | 89.0001.011 |
| Title | Keuffel & Esser Thacher’s (Cylindrical) Calculating Instrument |
| History |
Exhibit text: "Dr. Makio Murayama rescued this cylindrical slide rule from among discards in Surplus. It is one of the most sophisticated developments of the slide rule and was soon to be replaced by compact electronic calculators." The cylindrical slide can be moved by rotation or in and out longitudinally. It has twenty triangular wedges on it. The cylindrical slide has two complete logarithmic scales. When the slide is moved to match the wedges, normal slide rule operations are available but with great accuracy (to four figures). Edwin Thacher patented this design in 1881. The 1927 Catalogue of Keuffel and Esser Company, makers of drawing materials, surveying instruments, and measuring tapes, advertised Edwin Thacher's Calculating Instrument as having sufficient accuracy "for nearly every requirement of the professional or business man." Scientists also used the sophisticated slide rule, as a tool for solving trigonometry formulas, making and applying tables, and converting weights and measures, for example. Thacher's Calculating Instrument made difficult mathematical calculations easier avoiding, "the tedious drudgery of calculation," boasted the catalogue. The instrument is accurate to four or sometimes five decimal places and is considered the most sophisticated advancement of the slide rule until its replacement by electronic calculators. Thacher's invention begins with John Napier who in 1614 discovered the logarithm, which made it possible to perform multiplication and division by addition and subtraction. Logarithm is the exponent indicating the power to which a fixed number must be raised to produce a given number. Later the slide rule reduced even further the work of such complex computations by reducing the calculations to the mechanical equivalent of addition and subtraction. Thacher's cylindrical calculating instrument made vast improvements on the straight slide rule achieving overall greater accuracy. Thacher's instrument has 18-inch-long scales on two cylinders -- one external segmented cylinder that rotates, and a moveable internal cylinder that also rotates. Encircling the internal cylindrical slide are two complete logarithmic scales on the framework of 20 triangular bars. The internal cylinder also bears a slide rule scale. Thacher's instrument scales have an equivalent length of 30 feet, much longer than that of a straight slide rule, enabling the instrument to achieve very high accuracy. Thacher patented his calculating instrument in 1881. |
| Description |
Dark wooden case, hinged lid and hook closure. Inside lid is small K&E nameplate and paper label with K&E information and drawing of their factory. Instrument is mounted on wood with directions laminated on the base. Instrument is cylindrical with inner drum that turns and wedges with measurements and numbers on them. Component Parts: 89.0001.011.00.1 - Calculating Instrument 89.0001.011.00.2 - Wooden Case |
| Other Name | Calculator |
| Date | ca.1927 |
| Organizations | NIH; NIDDK (National Institute of Diabetes and Digestive and Kidney Diseases) (1988-present) |
| Buildings | Building 6 |
| NIH Property # | none |
| Old NIH Property # | none |
| Serial # | 3609 |