[Extract]

In my former Letter I said, that "the Harbor [of Boston] might be blocked up; and both Seamen and Soldiers made Prisoners at Discretion"; which seems to you incredible: ー Please, to read at your Leasure the following Explanation: ー There are but two Channels, through which Ships of Burthen can pass to and from Boston: ー One of them runs between. the west Head of Long Island, and the Moon, (so called) and is about a Mile across: ー This Channel is too shallow for any Ships of War above 20 Guns: ー The other runs between the east Head of Long Island, and the south Point of Deer Island; and is about a Mile & half from Side to Side: ー This, the only Channel through which capital Ships can pass, leads (outward bound) through the Narrows (so called) between Gallop's Island and Lovel's Island; where the Channel is not wider, than the Length of a 50 Gun Ship. ー In the opening between Gallops Island & George's Island, is Nantasket Road; where, one, is always, and at present, five Men of War are stationed, to gaurd the Narrows from being stop'd up:

Upon the foregoing Facts, I thus reason:

The Moon Island communicates with Squantum Neck; at low Water, almost dry shod: A defensible Fort, therefore, upon Squantum, may be so placed, as to secure a Retreat not only from the Moon, but from Squantum to the Main: ー one upon the east Head of the Moon, and another, if found necessary, upon the west Head of Long Island, secures the Passage between, and covers a Retreat from the Latter to the Former: Another upon the Summit in the middle of Long Island covers the Shore on each Side; so, as that no Force can land without being greatly anoyed, if not entirely prevented. Another strong Battery from 20 to 40 Peices of heavy Cannon at the east Head of Long Island; commands, not only the Ship Channel, but the Narrows, and Nantasket Road, so that no Ship can remain there with Safety; and consequently, by sinking Hulks in the Narrows we might prevent any Ship of Force from going out or coming in. ー If the Passage thro' the Narrows is not stop'd, I am sensible, a Ship with a fresh Gale of Wind, and flood or Ebb Tide, which is rapid between Long Island & deer Island, might run through without any great Hazard; but, after the east Head of Long Island is fortified, I can forsee Nothing to hinder, the Narrows being reduced to such a Draught of Water, as that, no Vessel of any considerable Force, can pass through there ー This, being effected; as I said above, both Seamen and Soldiers, if they dont escape, by a timely Flight, must become Prisoners at Discretion.

I have been told, there is in one of the English Magazines, an accurate Draft of the Harbor: ー If you can procure it, upon Examination, you may determin[e], the Distance and Depth of Water between the Islands aforesd with Precision; and consequently, whether such a Scheme is practicable or not.

I have thought, and said from the Beginning, that Row Gallies must be our first mode of Defence by Sea; it gives me therefore, Pleasure to hear, our worthy Friend Doctr F[rankli]n is employed in constructing some for the City of Phildia: ー I wish I had the same Employment here; for I am very sure, twenty of them, under proper Direction, would have taken or destroyed all those Cruisers and Cutters, that have infested, and done so much Damage in the Vineyard & long Island Sounds in the Course of the Summer past; besides, being a safe Convoy to our Provision Vessels. ー When I first proposed the Scheme to our Comtee of Safety, it was objected, that, we had no Body skilled in the Construction of them: Afterwards I heard of a Ship Carpenter, just escaped from Boston, who had been several Years a Prisoner in a turkish Row Galley, and had formed a compleat three feet Model of one: ー It was then objected, that, heavy Cannon, and Powder were wanting: ー An insuperable Objection, most certainly; which I hope will soon be removed.

Several Vessels have lately arrived in Boston from England; but the News they bring is industriously secreted: ー The sullen Silence, and dejected Countenances of the Officers, give Rise to various Conjectures: ー God grant: the Truth may be a Dissolution of a venal P-t, a disbanded Army, and an Order for the Ships and Troops here to return imediately Home.