Draft of MINT00617 (Mint 19/2/311)
Mint Office 12 Apr. 1714
May it please your Lordship
Since I attended your Lordship last, I caused a new furnace to be built in order to a further trial of what may be done by casting of copper into barrs for making of copper money. But in the mean time upon assaying the half pence of which I shewed your Lordship a specimen, I found the copper coarser then it was by the assay before casting. Whereupon I ordered the Queen's founder to supply me with such barrs as would fully endure the assay by the hammer: but he has not yet produced any tho it be about three weeks since I gave him the order. Whence I suspect that in the specimen of half pence which I shewed your Lordship, he put in some Tynn without my knowledge tho I stood by to see him cast that copper &. He seems to be at a stand in casting fine copper without mixture so as to make it runn close & fully endure the Assay by the Hammer: which makes a further trial unnecessary. Mr Kemp agrees with me that the proper assay of fine copper is by the hammer. If the barrs or fillets of copper be made by hammering & be assayed by the hammer, the money will be of the same fineness with the copper money of Sweden & with that of King Charles II: If they be cast, it will scarce be so fine. In the first case the workmanship as well as the metal will cost more & the work be more beautifull & the assay more certain & the method of coynage more easily setled then in the second. In the secon an Assay by refining as well as by the hammer may be usefull. But as Gold & Silver is not received to be coyned untill it be made fit to be received so it should be in copper. I am
My Lord
Your Lordships most humble
& most obedient servt
Is. Newton
Source
MINT 19/2/338, National Archives, Kew, Richmond, Surrey, UK12 April 1714, c. 348 words.