Robert Treat Paine Papers, Volume 3
The Bearer of this Mr. Hopkins tells me he took very particular notice of the late invented light Field pieces in use in the English Army 287and can furnish the necessary Directions for making and mounting them. He is also of Opinion that he can suggest a very considerable Improvemt. If these pieces are so light and handy and their Operation so great as he describes I think it will be well worth while to introduce them into our Army. Mr. Hopkins is a very ingenious Man and firmly attached to his Country. I am Sr. Your most obedt. Servant
| Nature of guns | Length of barrs. in the clear for | The thickness of the Barrs. | Diameter of the Shot |
| 1/2 pounder | 3.81 | .305 | 1.526 |
| 1 | 4.785 | .383 | 1.914 |
| 1 1/4 | 5.178 | .414 | 2.071 |
| 1 1/2 | 5.502 | .44 | 2.201 |
| 2 | 6.057 | .485 | 2.423 |
| 2 1/2 | 6.52 | .522 | 2.61 |
| 2 3/4 | 6.735 | .539 | 2.694 |
| 3 | 6.922 | .554 | 2.769 |
| 4 | 7.627 | .61 | 3.051 |
| 6 | 8.737 | .699 | 3.495 |
| 8 | 9.57 | .766 | 3.828 |
| 9 | 10 | .8 | 4. |
| 10 | 10.354 | .828 | 4.142 |
| 12 | 11.005 | .88 | 4.402 |
| 16 | 12.114 | .97 | 4.846 |
| 18 | 12.585 | 1.006 | 5.034 |
| 20 | 13.05 | 1.044 | 5.22 |
| 22 | 13.47 | 1.078 | 5.388 |
| 24 | 13.92 | 1.114 | 5.568 |
| 32 | 15.262 | 1.221 | 6.105 |
| 42 | 16.917 | 1.353 | 6.767 |