Essay-Master, an officer under certain corporations, intrusted with the care of making true touch, or assay, of the gold and silver brought to him; and giving a just report of the goodness or badness thereof. Such is the assay-master of the mint in the Tower, called also assayer of the king.

The assay-master of the goldsmith's company is a sort of assistant-warden, called also a touch-worden, appointed to survey, assay, and mark all the silver-work, &c. committed committed to him. There are also assay-masters appointed by statute at York, Exeter, Bristol, Chester, Norwich, Newcastle, and Birmingham, for assaying wrought plate. The assay-master is to retain eight grains of every pound troy of silver brought to him; four whereof are to be put in the pix, or box of deal, to be re-assayed the next year, and the other four to be allowed him for his waste and spillings.

Note. The number of pennyweights set down in the assay-master's report, is to be accounted as per pound, or so much in every pound of 12 ounces troy. For every 20 pennyweight, or ounce troy, the silver is found by the assay to be worse than standard or sterling, sixpence is to be deducted; because every ounce will cost so much to reduce it to standard goodness, or to change it for sterling.

In gold, for every carat it is set down to be worse than standard, you must account that in the ounce troy it is worse by so many times 3s. 8d.; and for every grain it is set down worse, you must account it worse by so many times 1½d. in the ounce troy; and for every half grain ½d.: for so much it will cost to make it of standard goodness, &c.