Dear Sir

I receiv'd yours of the 20th instant last Saturday After the post was gone or I should have answer'd it immediately. ー You desire me to send you the weight and bore of the Iron Ho[w]itzers we have here ー we have none. Colo [Richard] Gridley had two cast but they were never us'd ー Iron Ho[w]itzers are so unweildy from their weight that they are entirely exploded in the British Army ー a ten Inch will weigh 28.0.0  8 Inch 1500, & 5½ 1000. whereas a Brass 8 Inch Ho[w]itzer will not weigh more than 450 or 500, 5½ Inch 280 or 300

		Their Dimensions
8 Inch			5½ Inch
		Inches			Inches
length of Chamber		8	length of Chamber		6 6/10
Diameter ditto		4	Diameter do		2 8/10
from the Chamber to the muzzle or the whole length of the bore		24	from the Chamber to the Muzzle or the length of the bore		16 5/10

The ten Inch Ho[w]itzers have such great re-action that will break any field Carriage whatever therefore they are laid aside. ー 8 Inch and 5½ to fire at Ships or to fire case shot in the field are some of the best peices of Artillery now us'd. ー At the air Furnace in this city we have cast four 5½ brass Ho[w]itzers as good as those cast a[t] Woolwich, and in the course of this week we shall cast as many more ー I have prov'd them and find they will elevate to an angle of 25 degrees, project a Shell a mile and 45 degrees 1 mile and ½ ー The Carriages on which these are to be mounted are not yet finish'd which has prevented my making more accurate Experiments, on a point blank range or at small elevations ー I have no doubt that we should be able with certainty to drive a Shell thro' the side of a Ship at the distance of six or seven hundred yards ー with an 8 Inch 1000 yards ー In your Letter of the 20th June you say we cant get Brass ー Mr Byers a founder in this city tells me that he has no doubt but in a little time he could procure Copper enough to cast 80 or 100 Six pounders each of which will weigh dble the 5½ Ho[w]itzer ー There is a large quantity Of Copper at Boston, which could be appropriated to no better use than to be cast into Cannon ー There is a Copper mine in the Jersies which might be work'd on this occassion ー there are a great number of Stills Which are only a pest to society which ought to change their form ー If possible all our field Artillery small mortars & Ho[w]itzers should be brass ー our heavy mortars and Cannon, Iron ー It pleases me much to hear that you cast good 18 pounders &c at Philadelphia ー The buisness of casting Cannon and making fire arms is of infinite importance to this Continent and cannot be too much encourag'd ー The 24 pounders at this place are too heavy, they weigh 51.0.0 I have seen some Very fine 24 pounders belonging to Rhode Island which weigh'd 40.0.0 which is light enough for so large a Cannon ー we have a considerable number of 32 pounders which weigh about 50.51.52 hundred each ー The air furnace in this City also one at Newark in the Jersies about nine miles distance are in good order and I make no doubt will be able to cast you any number of field p[ie]ces either brass or Iron ー If there is any thing further in this way in which I can be of any service, I shall with pleasure do it You will 'ere this heare of the hellish plot At this place in Consequence of some of the Amiable Kings money liberaly distributed here ー and also of the Spirited Conduct of our friends at Boston in driving away some of the Kings ships, but Not perhaps of two more Highland transports which were taken there last Monday which is as follows communicated to me by a letter dated Boston Monday 11 oClock ー June 17 ー

This makes five Sail of Vessels with highlanders that have been taken ー I think they open the Campaign badly.

I am Dear sir with Respect [&c.]