To the most Honble the Earl of Oxford & Earl Mortimer Lord High Treasurer of great Britain

May it please yor Lordp

I humbly beg leave to lay before yor Lordp that the Master & Worker of her Majts Mint is not obliged to receive all the Gold & Silver brought into her Mats \Mint/ to be coyned. If any gold be brought in which is not tough, he returns it back to be toughne{illeg}|d| at the Importers charge tho it be standard. If any gold {illeg}|or| silver be not eavenly mixed he returns it back to be remelted at the Importers charge. If it be not neare to standar{t}|d| he returns it back to be refined at the Importers charge. And to judg whether it be fit to be received or returned back is left to his discretion. And by parity of reason he should not be obliged to receive all sorts of copper to be coyned. If it be not fine or not tough & malleable or ill coloured or otherwise faulty, he should be at liberty to return it back to be made fit for the Mint at the Importers charge. Otherwise it will be difficult {to}|&| scarce practicable to coyn the money of good malleable copper without allowing for the charge hazzards & loss attending such an undertaking.

There is an assay of copper by refining a small parcel & then recconing what will be the wast charges & trouble in refining a Tunn of {illeg}|su|ch copper. And such an assay is usefull in buying {f} coarse copper to be refined but is of little or no use in buying fine copper, nor proper for the Mint. The price of fine copper depends upon the malleability, & two parcels of fine copper equally fine, may differ very much in their malleability & by consequence in their price. Copper refined to that degree & in that manner as to be malleable without cracking when red hot is the fittest material for manufacturing into all sorts of copper vessels & by consequence for money. The Swedish copper money is of this standard; And such copper is usually valued at about 1112d per lwt. And if it be made still more soft & malleable the wire-drawer may value it at two or three shillings per lwt because of its fitness for his use. Tis the ductility that makes it usefull & the usefulness that sets a price upon it & the trial by hammering & bending hot & cold that determins the ductility. This is the assay by which Refiners of Copper know when their Copper is fully fine & ready to vitrify & by consequence the proper assay for receiving fine copper into the Mint. For it determins the fineness & the malleability at once, no coarse copper being malleable.

By the estimates of Workmen the charges of repairing & fitting up the houses in the Irish Mint for a coynage of copper, will amount to about 146li. And the putting up a furnace in the melting house with all things answerable for making an experiment by casting will cost about 32li more. And a small parcel of copper for making an experiment may cost about 20li more. If yor Lordp please to impress 200li to me for this service \upon accompt/ it may be repaid out of the copper coynage

All wch is most humbly submitted to yor Lordps great Wisdom

Is. Newton


[1] Mint Office 12 Mar. 1713.

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