Note by John Cartlitch on the remedy for guineas and Irish halfpence
If a ℔ Troy of Gold be cut into guineas, then the weight of each guinea will be grains, or .
If 20 grains remedy be allowed per ℔, aguinea may weigh from grains or for the heaviest, to for the Lightest.
guineas each weighing 130 grains, will weigh exactly 25 grains above a pound Troy:
And guineas each weighing 129 grains will be grains lighter than a ℔ Troy. So that a guinea should alway weigh betwixt 129 and 130 grains.
If a ℔ Troy of Gold be cut into guineas, and each gain be valued at £1:1. then
Hence in practise, ℔ odd grains may be always valued at 2d; the error in adwt amounting only to . but in an oz. it will be .
According to the Warrant for Coining Copper for Ireland, an Irish halpenny should weigh drams; and the remedy per ℔ Averdupois (being ) is half-penny.
Average of the lightness per ℔ upon ℔ whole Coinage in 1736 is grains; And this fraction is a profit to the bank of 14 oz. 1dwt & 18 grains of Gold = £54: 18: 4
<5v><text in Unknown Hand (1) begins>a Paper by Mr Cartlitch concerning the standard
<text in Unknown Hand (2) begins>Mint Paper In Conduitts Hand
Source
MINT 19/5/5, National Archives, Kew, Richmond, Surrey, UK1696-1727, c. 226 words.