What is "assay master"

Assay \As*say"\, n. [OF. asai, essai, trial, F. essa. See Essay, n.]

1. Trial; attempt; essay. [Obs.]
   --Chaucer.

   I am withal persuaded that it may prove much more easy in the assay than it now seems at distance.
   --Milton.

2. Examination and determination; test; as, an assay of bread or wine. [Obs.]

   This can not be, by no assay of reason.
   --Shak.

3. Trial by danger or by affliction; adventure; risk; hardship; state of being tried. [Obs.]

   Through many hard assays which did betide.
   --Spenser.

4. Tested purity or value. [Obs.]

   With gold and pearl of rich assay.
   --Spenser.

5. (Metallurgy) The act or process of ascertaining the proportion of a particular metal in an ore or alloy; especially, the determination of the proportion of gold or silver in bullion or coin.

6. The alloy or metal to be assayed.
   --Ure.

   Usage: Assay and essay are radically the same word; but modern usage has appropriated assay chiefly to experiments in metallurgy, and essay to intellectual and bodily efforts. See Essay.

   Note: Assay is used adjectively or as the first part of a compound; as, assay balance, assay furnace.

   Assay master, an officer who assays or tests gold or silver coin or bullion.

   Assay ton, a weight of 29,166 2/3 grams.