in navigation, is used for a pram, or ferry-boat.

in brewing, a large flat kind of tub, or vessel, wherein the wort is put to stand and cool before boiling. The ingredients of beer pass through three kinds of vessels. They are mashed in one, worked in another, and cooled in a third called bac or coolers.

in distillery, vessels into which the liquor to be fermented is pumped from the cooler, in order to be worked with yeast.

BACK-Maker, is one who makes liquor-backs, under-backs, coolers, mash-tuns, working-tuns, &c. for the brewers. The workmanship is partly carpentry, in a particular manner, for it must be tight enough to hold liquor; and partly cooperage, viz. the mautun, or vat, which is hoop'd. There are not many of this trade; and it requires chiefly strength, with a little art. A small stock of stuff, besides tools, will set a man up tolerably well; but, with 200l or 300l, he will make a good figure in business.