Passages from the Life of a Philosopher

back with him to Russia such an account of the Mechanical Notation as might facilitate its teaching in the Russian Universities. I regret that it was entirely out of my power to assist him. These, however, were so extensive that it was impossible, without very great inconvenience, to exhibit them even in my own house. 〈THE LOAN OF OTHER CALCULATING MACHINES OFFERED.〉 I therefore wrote to Mr. Gravatt to offer him the loan of the following property for the Exhibition:— 1. A small Calculating Machine of the simplest order for adding together any number of separate sums of money, provided the total was under 100,000 l., by Sir Samuel Morland. 1666. 2. A very complete and well-executed Machine for answering all questions in plane trigonometry, by Sir Samuel Morland. 1663. {155} 3. An original set of Napier’s bones. 4. A small Arithmetical Machine, by Viscount Mahon, afterwards Earl Stanhope. Without date. 5. A larger Machine, to add, subtract, multiply, and divide, by Viscount Mahon. 1775. 6. Another similar Machine, of a somewhat different construction, for the same operations, by Viscount Mahon. 1777. 7. A small Difference Engine, made in London, in consequence of its author having read Dr. Lardner’s article in the “Edinburgh Review” of July, 1834, No. CXX.