Yesterday I had the pleasure of receiving your Excellency’s Letter of the 31st Ulto., and thank you for the polite manner, in which you received the Gentlemen I took the liberty of introducing to you. An introduction to Dr. Franklin is the wish of most persons going to Philadelphia; and the application for letters for that purpose is generally so pressing, that it is difficult to parry it. This I hope will apologize for the frequency of them, an inconvenience, to which eminent characters are unavoidably subject.

On enquiry of Mr. Gannett, a Secratary, and the Librarian of our philosophical Society, I find he has not received the second volume of your Transactions, which you mention you sent to the Society, and had not heard of its arriving. The volume you were so obliging as to send to me, and which by your letter appeared to be for me, I received; and I soon after thanked you for it in a Letter, written in answer to yours, and which accompanied that volume. I am Sorry the volume you intended for the Society has miscarried.

The french work sur les Arts, & les Metiers, which you mention you have bequeathed by your Will to our philosophical Society, the Society is not possessed of; and it is my wish, and without doubt will be theirs, when your letter shall be communicated to them at their next meeting in August, that they may for a long time be kept out of possession of it. Mr. Gannett’s Billet, in answer to mine of this day relative to those books, is enclosed.

I observe you expect to be free from publick cares in a few months. You certainly have a right to be so, considering the long and important services you have rendered your country: but I fancy they will find, especially at this crisis of their affairs, more public business, and not less important than the past, for a Gentleman who knows so well how to execute it. If however you choose to rece from Politicks, it will be a happy circumstance in a philosophical view as we may expect many advantages to be derived from it to philosophy.

I have read, and repeatedly read, your ingenious queries concerning the cause of the earth’s magnetism and polarity, and those relating to the theory of the earth. Be the former you seem to suppose, that similar magnetism and polarity may take place, not only throughout the whole solar system, but all other systems, so that a compass might be useful, if a voyage in the starry regions were practicable.

I thank you for this noble and highly pleasurable suggestion, and have already enjoyed it. I have pleased my self with the idea, that when we drop this heavy earth-attracted body, we shall assume an etherial one and in some vehicle, proper for the purpose, perform voyages from planet to planet with the utmost ease and expedition and with much less uncertainty than voyages are performed on our ocean from port to port. I shall then be very happy in making such excursions with you: when we shall be best qualified to investigate causes, by discerning with more clearness and precision their effects. In the mean time, my dear friend, until that happy period arrives, I hope your attention to the subject of your queries will be productive of discoveries useful and important such as will entitle you to a higher compliment than was paid to Newton by Pope, in the character of his superior Beings: with this difference however, that it be paid by those Beings themselves.

This will probably be delivered to you by Mr. John Stewart, a grandson of the late Captn. Erving. He is appointed Collector at Bermudas, and will embark for that Island after he has seen Philadelphia.

Mrs. Bowdoin present to you her very particular regards, and hopes to see you once more in Boston. With real and the greatest esteem, I am, my dear Friend, Your Excellency’s most obedient affectionate humble Servant.