Copy of letter concerning the costs associated with coining copper

Author: Isaac Newton

Source: MINT 1/7/60-1, National Archives, Kew, Richmond, Surrey, UK

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- Revision History
  - 17 October 2016
    - Transcribed by Will Scott
  - 22 December 2016
    - Metadata amended by Will Scott
  - 9 January 2017
    - Catalogued by Will Scott
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<60>

To the Most Honourable Robert Earle of Oxford &c^a:

In Obedience to your Lordships Verbal Order of Reference concerning the best manner of Importing Copper into the Mint to be Coined into Copper money of a certain standard and whether such an Importation may be made free We humbly represent to your Lordship that if Copper be mixed with any other base Mettal or semimetal it will not endure the Hammer when red hott butt will fly in pieces: so soon as it is refined by the Copper Workers to that degree as to be pretty well purged from all other base Metatals it begins to endure the Hammer when red hott without flying in pieces but not without cracking, and for making vessells and other utensills of copper there is no need to refine it higher.

They that Work Copper from the Oar when they have brought it to such a degree as they call fine copper, sell it to those who have Mills for manufacturing it and expose it to sale in their Warehouses in London and such Copper is worth from 95^li to 100^li per Tun and very little of it is worth above 100^li per Tune. This is commonly called fine Copper But that of 05^li. per Tun will scarce hammer without cracking and then it is worth about 11 $\frac{1}{2}$ per pound weight or about 107^li per Tun or thereabouts.

Refiners of Copper by refining a small part of any Mass can make an Estimate of the Charge of Refining the whole mass and how much fine Copper it will produce But the best Way of making such an Assay is not yet agreed upon when it shall be agreed upon & brought into Common use it may be then considered whether the Master and Worker shall be allowed to buy course Copper by such an Assay and putt it out to Refine it with publick money and what he shall be allowed in his Accounts for the refineing thereof according to the several degrees of the Courseness, and what for the waste by evaporation, In the mean time the Master or any other person may buy course Copper, put it out to be refined and send it to the Mint to be Coined.

The Malleability of the Copper depends not only on the fineness of the metal or freedom from other Metals but also upon the manner of refining it for if it be refined with seacole it will nott be Malleable and fitt for working though it be fine It may be refined with sea coale till it begins to be fine and then it must be wrought with charr'd coale till it be fully fine and the charr'd Coale of Wood is better than sea coal charred. Also the melting diminishes the Malleability, especially if it be melted with too much heat And for these Reasons the Assay by the Hammer is the best and surest for the Mint.

If it shall be thought fitt that Copper Money be made of such copper as in hammering when red hott will crack butt not fly in pieces, it may be brought at the Copper warehouses in London; if of such Copper as will hammer red hott without cracking it must be had of those who refine Copper.

<61>

In the Reign of King Charles the Second a pound weight of Swedish Copper was cutt into 20{^d} the Copper and making the Blanks cost 18^d. the stamping 1^d and a penny remained for other charges; this Copper was malleable so as to hammer red hott without cracking

If it be thought fit that the Money now to be coined by of like fineness so as to endure the same teste the Copper will cost 11{^d} $\frac{1}{2}$ per pound weight as above and the Coynage about 6^d or 6^d $\frac{1}{4}$ without edging or 7^d. with edging And if a pound weight not edged be cutt into 20^d or a pound weight edged be cutt into 21^d there will be an Excess of 2{^d} $\frac{1}{2}$ per pound weight for purchasing Mills and presses and Cutters and flatter and setting up a Copper Mint and paying Clerks and incident charges of Assaying, weighing, telling, porterage, baggs paper and packthread, putting off, &c. But if it be thought that the Copper be only so fine as to endure the Hammer when red hott without flying in pieces tho not without cracking a pound weight may be cutt into 19^d not edged or 20^d edged.

The Mills and Presses and other Engines for setting up a Copper Mint will cost six or seven hundred pounds and three farthings per pound weight in Coining an hundred Tuns will pay that charge And when that charge is paid the weight of the money may be a little augmented.

If the Blanks be so thick or the Impression rise so high as to straine the Dyes or Cutters and make them more apt to breake then in the Coinage of Gold and Silver or the casting into Barrs prove so difficult as to make above one half of the Barrs become scissell, the charge of Coinage must be proportionably augmented for which reasons the Charges of Coinage cannot be positively sett without Experience in Coining some Tuns of Copper Money.

The Weight of all the Copper received and the Weight and Tale of all the copper money coined may be Entered into Books and in the Accounts of the Master and Worker and the surplus above all charges may be paid into the Exchequer.

All which is most humbly submitted to your Lordships great Wisdome

Ianry: 22^d: 1713