Robert Treat Paine Papers, Volume 3
I yesterday recd. yours by Melchor Saladin & immediately procured the within discharge. He brought with a John Haine who & said that after your Letter was closed you sent a verbal Message desiring that he might likewise be discharged & put into your Service. He was so positive that I gave Credit to him & hope it is right. I shall direct them to make the best of their way to you. I understand by them that your new furnace is built & ready for blast. I hope you will take every precaution to prevent Miscarriages. When you consider the 336importance of your Undertaking to the public as well as to your selves you will not wonder at my importunity with you to attend critically to the quality of the metal, so large a proportion of the Guns made in the Furnaces here have failed in proving that I am satisfied of the truth of what Mr. Mathews told me that the great Art of Making Cannon was the getting the Metal to a due Temper. What should be the reason that Iron when Cast into a thin Pot or Kettle Shall be fine & close grained & very strong & tough, & yet when Cast from the same furnace & the same sort of Ore into a large Cannon it is course & open grained & brittle. I think it Shews that some further preparation is wanting for Iron Cast into a large body than a Small one; Stone lime is found to be a great refiner of Iron. I suppose it is generally used At the furnaces or rather the Lime Stone is used. Mr. Wm. Henry of Lancaster is of Opinion & I think with great reason that the burnt Lime should be put in rather than the Stone, because before the lime stone is burnt so as to operate on the Iron the Ore is Melted & gone off, but the Lime operates immediately in Absorbing the Sulphur Arsenic & other heterogenous Matter. He is also of opinion that the quantity put in is never Sufficient. Some Experiments he has tryed of the Effects of Lime in toughning Iron Ore are very Satisfactory. I dont undertake to direct or instruct you in yr. business but if I should drop a hint to yr. Advantage you will not take it amiss. I wish a through tryal was made of the Advantage of putting in very large quantities of Lime into the furnace. I really believe you would find your