Draft of MINT00617 (Mint 19/2/311)

<309r>

To the Most Honourable the Earl of Oxford & Earl Mortimer Lord High Treasurer of great Britain

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 & coyning copper money out of those barrs, 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 Mr Bagley the founder to supply me with such barrs as would fully endure the assay: 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 the copper &

He seems to be at a stand in casting fine copper without mixture so as to make it run close & fully endure the assay by the hammer after casting; Which makes a further tryal unnecessary. Mr Kemp agrees with me that the proper assay of fine copper is by the hammer. If the 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: If they be cast it will scarce be so fine. in the first case the workmanship as well as the metall 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 second an assay by refining as well as by the hammer may be usefull. But as there is a power in the Mint of refusing such gold & silver as is not made fit to be received so it should be in Copper.

If the

<310v>

Sir Isaac Newton
Report about Coyning Copper Farthings & halfe pence