I have the Honor to address you, at the particular Request, and in Consequence of a Letter which I have just received from His Excellency the Count de Rochambeau, inclosing to me the Copy of a Correspondence between him & you relative to the Operations of the Fleet under your Command on the Coasts of N. America—Wherein you mention to him a Wish, that while you Fleet should remain in the Neighbourhood of Boston, you might be enabled to make a Stroke at the Enemy’s Post of Penobscot—and in the Discussion of which Point the Count de Rochambeau has referred you to my Opinion upon that Enterprize.

While I applaud, Sir, the generous Disposition declared in your Intentions for our Assistance, Candor requires me to be very explicit upon the Subject—I am obliged therefore to say that it is my decided Opinion, that, considering the Hazards that will attend the Enterprize, the Object is by no Means equal to the Risque that will attend the Attempt.

Among many Reasons, which influence my Mind in forming this Opinion, The great & very principal one appears from your own Letter to Count de Rochambeau—you mention to him that you expect immediately to be followed into these Seas by a superior British Fleet—Admitting this event to take place, & that your Fleet should have proceeded to Penobscot (which is near one hundred Leagues from Boston,) ( the only secure Harbour which you will find upon all those Eastern Shores) which lies almost at the Bottom of a deep Bay, it appears to me that your Fleet will be placed in the great[est] Hazard of being totally destroyed; for in that Situation they will be completely embayed and a brisk So. Westerly Wind, which will be most favorable for the British Fleet from New York and which would bring them into the Bay in a short Time, would be directly opposed to your Escape—so that was you to receive the earliest Intelligence of the Enemy’s Fleet leaving New York, under such Circumstances, yet you could not avail yourself of the Information, and at the same Time would be placed in a position where no Harbour or Fortification could give you any protection or Shelter.

Was this Argument of Danger to His most Christian Majesty’s Ships not sufficient to govern your Mind, I could mention that the Time that must be employed on this Attempt, will probably be much greater than you seem to apprehend. A Month is as short as I should estimate, taking together all the necessary preparations & little cross Events that must probably interpose; for I have not an Idea of the Object being to be attained by a Coup de Main; as I am lately informed by good Intelligence that the Fort is the most regularly constructed & best finished of any in America, is well situated, & garrisoned by the 74th Regiment, consisting of 800 Men, which will require a regular Siege, to be conducted by cautious Approaches, a considerable Addition of Men to the Number of Troops which are on Board your Fleet, with their necessary Cannon & Mortars, Stores &c. the whole of which in all probability, was the Siege to be undertaken, and your Fleet obliged to make a sudden Departure, must all be sacrificed, as their Retreat by Land (as has been heretofore experienced) would be almost totally impossible and impracticable, to be effected through a Country which is as yet a mere Wilderness of large Extent, & difficult passage.

Even supposing the best, that the Attempt should succeed and the Object be gained, I am much in Doubt, whether, without a naval Force, to be maintained on those Coasts we should be able to retain the Post; as it would ever be subject to a renewed Attempt from the Enemy, in case we should keep up a Garrison there; or in Case of Evacuation, they might at any Time repossess the post, and continue the same Annoyance that they now give us.

Under these Considerations (without giving you any further Trouble) it is my decided Opinion that the Object in Contemplation is not of Importance sufficient to justify the Hazards and Risques, which must probably be encountered in the Attempt to obtain it.

While I offer you this Opinion, Sir, I beg you will esteem it as coming from a Heart not only candid, but at the same Time penetrated with a Sense of the highest Gratitude to you for the noble Offer of your Assistance, which it is our Misfortune, that, under present Circumstances, we are not able to avail ourselves of.

After giving you the foregoing Opinion upon present Appearances, I have only to add that in Case Circumstances should turn up so differently to our present Ideas, that you should, with the Advice of General De Choissy, think the Attempt practicable, I can only refer you to the State of Massachusetts for such Aid in Men, Cannon, Mortars & Stores, as you shall judge necessary, it being the only practicable Mode in which I can co-operate with your Designs; and this Recommendation shall be most cheerfully given.

The Chevalier de la Luzerne has requested me to esbablish a regular Chain of Communication between my Head-Quarters & Boston, for the purpose of giving you the earliest Intelligence of every minute Circumstance that may occur respecting the Arrival or Operations of the British Fleet at New-York; and for the purpose of free Intercourse with you on any other Circumstances that may turn up. You may depend, Sir, that this Establishment shall be immediately formed; and that every Service I can possibly render you in this, or in any other Way in my power, shall be most cheerfully afforded. With the purest Sentiments of Respect & Esteem I have the Honor to be &c. &c. &c.