A party of citizens from this city who under an expectation of bing called by detachment on emergency to Fort Mifflin, were desirous of spending a day at the place and invited me to be one. Entertaining sentiments not favorable to Enterprise works, my views in writing to you are to represent the situation of a work already constructed, which is erected on a place very advantageous for the defence of the approaches to this city, and affording a very excellent school for the diffusion of the principles of defence if it were under adequate regulation.

My purpose is not to point out defects in the works as originally construed these are perhaps beyond my skill. Such as the works are, they are in a state of very great decay, and the artillery in a condition unfit to make half an hours opposition to an inconsiderable force if it were brought against the place. I see no reason, even in the event of an active war, to suspect that any force capable of proceeding so far up the Delaware would be sent from Britain; but that discretion which guards against the most remote contingences in war, would certainly render the only defensive position that could effectually check an enemy as complete as practicable.

The Garrison as I understood does not now amount to more than 50 to 53 men, out of which there is a detachment on the recruiting service; and thro’ whatever causes, there are on average ten always sick; so that the main guard has but one night in bed, which possibly may be one of the causes of sickness. The accommodations are ample for a more suitable number and 120 men would find under a rational discipline, wholesome employment for reasonable hours on the works, and yet be small enough with the aid of 200 or 300 militia to man them all in case of attack

There are but two small brass French 10 wick Howitzers that I saw; the superiority of the Sea Mortar is such that if there were a reasonable number of them here, they would be both effectual in case of need and contribute greatly to that confidence which is so essential to military discipline at a moment of trial. The guns on the ramparts consist of 24 & 32 pounders and are planted on those batteries which cover the passage of the Delaware and Mud Island; the old gun (36 pounder) called the Delaware which did the British so much mischief, and of which they broke the trunnions aftewards is lying in the mud in the bottom of the ditch; this gun which would induce favorable feelings in case of need, might be restored to service by hook-trunnions at a small expence. But there are two other particulars that require attention even on motives of economy and prudence. The guns all but two or three are mounted on carriages of such a construction and these so decayed, that their own recoil at the first shot must overset them. The difficulty of raising guns of such a weight at any time is great but in a rampart narrow and decayed, when the miserably constructed beds upon which they were originally placed are sunk in the earth, it would be utterly impossible to raise them in any time to render them useful or avert a storm. They seem indeed so constructed as if they were intended to be overthrown and to destroy those who were loading & firing them. The touchhole or vent of the gun is actually eight or ten feet above the level of the rampart, and the banquette or place upon which the men are to stand, is scarcely a foot above the rampart—the guns present something of the appearance viewed at the side as the enclosed sketch. The carriage is of wood two large cheeks with arches cut in them as described; the wheel behind was intended to traverse on a semicircle of Stone; the Stones are there, but about a foot too narrow for use and all out of their places; the wooden carriage rebounds on two axels on the upper face of two sleepers, which rest on brick work under the foot or talus of the parapet, and the other ends of which rest on the traverse wheel. I did not measure their height but the rough sketch of a human figure bears some proportion to the height of a man standing on the platform of the rampart, and the gun which he is to fire above his head. Beside that the carriages being thus ricketty in construction, they are rather or nearly so, and utterly unmanageable as they now are. This is the state of the guns that are there. Several of the batteries and of the Smaller bastions are naked. The Works erected in John Adamss days are faced with brick, one bastion admirable in its position is however so injudiciously constructed, that there is no work to cover its flank and there is so little slope in the outer talus, that men might be lodged under it without danger of any fire from above excepting Grenades: a sally port appears to be wanting in this bastion, or a small demi bastion on its northermost angle. The parapapet all around is nearly level in stead of being elevated inward in about the proportion of an inch or inch and half to the foot wide. The gates begun by Mr. Adams are unfinished and in fact had better never been built, for under the idea of producing a shewy Effect, the main gaitway is a near veneering of marble in rustic slabs, the joints in which now shew themselves, and that a pound ball would tear them to pieces. The Brick work of the arch of the maingate is exposed to the weather on its crown, and must fall in if not taken care of in time. The greatest evil for a garrison is the uncovered position of the magazine; it is a raveline on the right side of the main gate, the crown of this raveline is a diamond battery, but without guns of any kind and both faces of the raveline are Exposed to the Interior fire on the side next the Delaware, and on the side next to Philadelphia. In all other garrisons the magazine is in the most desired place, here it is in the most Exposed. It seems evident to be one of those works constructed in the Jobbing times of 1797-8—for the face of the raveline is of good brick, & by means of finishing in style they have finished the angles in stone, and so attentive was the Engineer or so skilful the builder, that they have left the quoins or corner stones so perfectly square and neat as to furnish ladders ready prepared for an external enemy to scale or for the garrison to escape—I made the experiment and ascended without difficulty to the crown of the parapet upon this ingenious ladder. The stones might have been at least chamfered off or bevilled, but it was too much trouble it is to be presumed.

This magazine battery is also adjoining the main gate and main guard—and as a 24 pound that would penetrate the wall in front, it would seem as if every thing incongruous was intended in its economy. A heavy earthen or coarse stone breast work or angular battery with two or three small traverses retreating to the flank of this magazine might be easily constructed in its front, which would cover it effectually, and it would conform to another which is thrown up in front of the gate, and which is in fact the best battery of the fortress tho’ in ruins. There is a small structure called a furnace erected outside the gate. I saw the name of J Adams on a piece of marble and J’ M’Henry tacked to it & Tousard fecit; and I was told it was for heating balls red hot—but it appeared to me rather an oven for baking bread, for balls could certainly never be heated there, much less made red hot. Furnaces for heating shot are essential for New York; and if there were four or six of the moveable furnaces such as the French use on the coast of Bolougne, they would be of great use on an emergency The quantity of Ball is not adequate to a two hours consumption; but I learn that more are sending and some powder. There is no grape, and if I am not misinformed there is none in the arsenal here. Permit me to suggest that, on the principles of war, and of a real economy, Grape should be made wholly of lead, and not of cast Iron. In calculating we must take the effect produced, and not the first cost. A bag of cast Iron grape of 120 balls, at the usual computation will throw ten at an object within the usual range with effect; the same number of leaden balls in a bag shot will throw one out of every five into its object; to that the proportion is as pie to wit of every five of lead to one out of 12 in iron; this is what an intelligent man tells me; the loss and the relative effect is therefore the real difference; the prime cost of lead & cast iron is easily ascertained and calculated.

While venturing to trouble you on a military subject permit to suggest that if you could without considering it in the least injudicious or improper, favor me for the regiment I command with the use of four, or if not four two brass field pices of artillery, I would be responsible for them and their return to the public when called for. I would ask no carriage nothing but the brass gun & the worm, rammers, sponge and drag ashes, nor the latter if requisite. There is a very strong desire here to reach some experience in flying artillery, as the impression appears to be that rifle men and flying artillery would be the best fortifications. It is with the view of encouraging this temper that I solicit this favor, at the same time that if you feel the least doubt of the propriety of it, I shall not be at all dissatisfied; but I need not say that we have nothing of encouragement nor even of utility to Expect from the State Executive. There are abundance of guns lying at the arsenal, and we should equip them with suitable carriages if we had them.

I am in treaty with Col. Tousard for his work on defence, it is very well adappted to the U States, if I were to purchase it and publish it might I calculate on any number of copies being taken by the public; I would endeavor to render it creditable to the country. I have in the press the first number of a military work with plates, on the lancer pike exercise, and its advantages. I mean to follow it with another on Cavalry exercise, having treatises that are very scarce and three of them not in the English language. The modern field discipline of the French is now translating here, and may be very easily accomodated to the discipline of militia, for which it was in fact proved in 1791 from the very necessity of the scare. Our militia would be exactly such troops as the French at Jamappe.

Excuse Yours faithfully