In addition to the honourable testimony of the Astronomer-Royal, in favour of the Pennsylvania Observers of the Transit of Venus, is the following eulogy of another eminent English astronomer,—as communicated by Dr. Franklin to Dr. T. Bond, one of the Vice-Presidents of the Philosophical Society, in a letter from London dated the 5th of Feb. 1772. The Rev. Mr. Ludlam, the gentleman referred to, and whom Dr. Franklin styles “a most learned man and ingenious mechanic”—in a paper published in the Gentleman’s Magazine (and a copy of which, subscribed by himself, was sent by him to the Society,) giving an account of the Society’s Transactions, more especially their Observations of the Transit of Venus,—applauds both the General Assembly and the late Proprietaries of Pennsylvania, for the countenance and assistance they gave to the making those Observations.——“No astronomers,” said Mr. Ludlam, “could better deserve all possible encouragement; whether we consider their care and diligence in making the Observations, their fidelity in relating what was done, or the clearness and accuracy of their reasonings on this curious and difficult subject.” He then mentions, in very honourable terms, the papers of Mr. Rittenhouse, Dr. Smith, Dr. Ewing, and Mr. Biddle, who drew up the several accounts of the Observations made at Norriton, Philadelphia, and Cape-Henlopen; and adds, that “they have very honestly given not only the Result of their Observations, but the _Materials_ also, that others may examine and judge for themselves; an example worthy of imitation by those European astronomers, who are so very shy of giving particulars, and vouch for their _Instruments_ and Observations in general terms.” The same gentleman, in a letter dated at Leicester (in England,) January the 25th, 1772, and transmitted to the Philosophical Society by Dr. Franklin, wrote thus:—“The more I read the Transactions of your Society, the more I honour and esteem the members of it. _There is not another Society in the world, that can boast of a member such as_ Mr. RITTENHOUSE: theorist enough to encounter the problems of determining (from a few Observations) the Orbit of a Comit; and also mechanic enough to make, with his own hands, an Equal-Altitude Instrument, a Transit-Telescope, and a Time-piece. I wish I was near enough to see his mechanical apparatus. I find he is engaged in making a curious Orrery. May I ask,” &c.