Sr., Philada. Octr. 25th. 1776

I have recd. yrs. of 15th Currt. & with great pleasure hear of the Success of the Cannon foundry at Salisbury. I have been informed that not one has burst in proving. If the proof be sufficient this is remarkable Success & will pay for transporting Coal a great distance. You will give me leave to be perticular on the Subject of proving the Cannon as it has fallen under my inspection here. When we first Contracted for Cannon in this State we did not determine the proof but only that they should be sufficient, for at that time there were so many Opinions what was the Woolwich proof that we left it unsettled, but we Since find that for 18 pounders & downwards they are the weight of the Ball in Powder two Balls & three hard Wadds & then a 2d. Charge of 2/3 wt. of Ball 2 Balls & 3 Wadds because the first Charge may crack the Gun tho’ not burst it & accordingly Messrs. Hughes & Co. of Maryland have proved all the Cannon they have made in that manner being 20 long 18 pdrs. for that State & the 12 pdrs. for the Frigate building there, & they are said to be exceeding good Guns & they have Contracted for that proof for all the 312Guns they are to make for Congress; the Cannon that have been made here have been proved with 3/4 wt. of the Ball in Powder 3 Balls & 3 hard Wadds & then a 2d. Charge of 2/3 & 2 Shott & 3 Wadds which I take to be as good a proof as the other because the severity of the proof consists in the resistance the powder meets in passing thrô the muzzle; but many of the Cannon made here have burst under this Operation; you say the Guns made at yr. Furnace were proved with a double quantity of powder & shott. I do not surmise that this is not a Sufficient proof, but as it is indeterminate I wish you to be ascertained precisely wt. it is. Some reckon 1/3 the wt. of the ball a proper charge for Action wch. I believe to be the practice & that with make the proof 2/3 & 2 balls wch. I do not think sufficient besides 3 hard Wadds is considerable addition. Another thing that requires attention is the quality of the Powder. A great deal made in this State & also some imported is exceeding poor. It has been Said that Some made with you has been bad, but if the Resolves of Congress respecting the Inspectors of Gunpowder be attended to, I hope that difficulty will be Soon cured; you will excuse my freedom on this Subject when you Consider of what importance it is that the Gun Should be Sound for Should Any burst on board a Ship it might destroy many lives occaison the loss of the Ship & discourage the Service: We hope Soon to hear that a convenient place is found for erecting a Stack sufficient for heavy Cannon. Perhaps they will never be more wanted than Next summer, & there are few matters that require more immediate attention.

Dft. ; addressed: “Govr. Trumbull. per Express”; endorsed.