Stanhope Demonstrator
The Stanhope Demonstrator was the first machine to solve problems in logic.[1] It was designed by Charles Stanhope, 3rd Earl Stanhope to demonstrate consequences in logic symbolically.
The first model was constructed in 1775. It consisted of two slides coloured red and gray mounted in a square brass frame. This could be used to demonstrate the solution to a
Construction
The device was a brass plate about four inches square which was mounted on a piece of mahogany which was three-quarters of an inch thick. There was a opening with a depression in the wood about one and a half inches square and half an inch deep. This opening was called the holon, meaning whole, and represented the full set of objects under consideration.[3]
A slide of red translucent glass could be inserted from the right across the holon. A slide of gray wood could be slid under the red slide. When the device was used for the "Rule for the Logic of Certainty", the gray slider was inserted from the left. When it was used for the "Rule for the Logic of Probability", the gray slider was inserted from above. The red and the gray sliders represented the two affirmative propositions which were being combined. Stanhope called these ho and los.[3]
At least four of the devices with this square style were built.
See also
- Logical piano
- Venn diagram
References
- from the original on 23 March 2023. Retrieved 20 February 2023.
...the first true logic machine, the Stanhope Demonstrator
- from the original on 15 February 2023. Retrieved 14 February 2023.
- ^ from the original on 16 February 2023. Retrieved 14 February 2023.
- ISBN 9781439865637
- ^ William Stanley Jevons (1877), The Principles of Science, Macmillan, pp. ix–x
- S2CID 159875267.
- The Science Museum, archivedfrom the original on 17 February 2023, retrieved 17 February 2023