[Description of a machine for teaching blind persons arithmetic] / [Thomas Grenville].

  • Grenville, Thomas, 1755-1846
Date:
[1793?]
Catalogue details

Licence: Public Domain Mark

Credit: [Description of a machine for teaching blind persons arithmetic] / [Thomas Grenville]. Source: Wellcome Collection.

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    and Defcription of it. This Machine remained in the Repoftory, and had been confiantly and uniformly admired by all who examined it, to the Tear i785> when the Society received another Letter from Mr, Grenville, informing them he had made a further Improvement in his Machine; which having been duly examined, the Society voted him their Silver Medaly and pur chafed one of his loft improved Machines, which is referved in their Repoftory, and of which a Defcription and Plate is annexed, with an hiforical Account of the Invention, communicated by Mr, Grenville. As a Confirmation of the Utility of this Machine, to Blind Perfons, it may not be improper to infert the following Letter, addreffed to Jonas Hanway, Efq. by Mr. Stanley. S I R,