Note 104 — MEMOIRS OF THE LIFE OF DAVID RITTENHOUSE; ANTERIOR TO HIS SETTLEMENT IN PHILADELPHIA.

In the earlier part of this interval of time, and before he became more seriously engaged in those great works and researches, the construction of his Orrery, and the Observation of the Transit of Venus with the operations preparatory to it, which about that time engrossed his attention, he occasionally amused himself with matters rather speculative than practical: though he very seldom devoted any considerable portion of his time to things which he did not consider as being in some degree useful.

The following is one of those instances in which his active mind was diverted from severer studies, to some objects of a more playful nature.

In the year 1767, some ingenious country-gentleman published in Messrs. Hall and Sellers’s paper, under the signature of T.T. the result of calculations he had made on Archimedes’s famous vaunting assertion, Δος που στω, και την γην κινησω. Mr. Rittenhouse published, some short time after, calculations (or rather the result of calculations) of his own, on the same problem. This appeared in a piece under the signature of “A Mechanic,” dated the 8th of October, 1767: and a reply to it, by T. T. dated October the 29th, appeared in the same paper. These little speculations will be found in the Appendix. It is not improbable that Mr. Rittenhouse, under the disguise of “A Mechanic,” appeared in print on this occasion, for the purpose of drawing the attention of ingenious men to subjects of this nature.