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The ART of Gaging of Vessels. CHAP. VIII. The Ʋse of the Line of Numbers, and the Lines on the Gaging Rod or Staff, and the Rules in Arithmetick in Gaging of all sorts of Vessels, (viz.) to Gage a Cube-Vessel, to Mea∣sure any Square-Vessel, and a Cylinder-Vessel; Also, Bar∣rels, Pipes, or Hogsheads; to Measure a Vessel part out, to Measure a Brewers-Tun, or a Mash-Fat, to Measure a Cone-Vessel, to Measure a Rising or Convex Crown; and also a Convex or Falling Crown in a Brewers-Copper; also a Brewers Oval Tun.
PROBL. I. The true Content of a Solid Measure being known, To find the Gage-Point of the same Measure.
THe Gage-Point of a Solid Measure is the Diameter of a Circle whose superficial Content is equal to the solid Content of the same measure; so the solid Content of a Wine-Gallon according to Win∣chester measure, being found to be 231 Cube-Inches: if you conceive a Circle to contain so many Inches, you shall find the Diameter thereof to be 17:15 by this Rule. Example. A Wine-Vessel at London is said being the 66 Inches in length, and 38 Inches in the Diameter, would contain 324 Gallons. If so, by the Line of Numbers we may divide the space be∣tween 324 and 66 into two equal parts, the middle will fall about 146, and that distance will reach from the Diameter 38 unto 17:15 the Gage-point for a Gallon of Wine or Oyl after London measure: the like reason holdeth for the like measure in all places. Thus likewise you may discover the Gage point for Ale-measure, an Ale-Gallon, as hath been of late discovered containing 282 Cubique-Inches; for as 1 is to 1:273, so is 282 to 356, 3 whose square-root is 18:95 the Gage-point for Ale-measure, because of Wast and Soil exceeding that of Wine above two Inches: or you may find it as before by the Content 256, 3 and the length 66, and the Diameter 38, as before. There are several other Rules to find it, but these may satisfy to save Prolixity, Mr. Phillips, and others, have found and proved by Example. That there is 288 ¾ Cubique Inches in an Ale-Gallon, which I believe is the Truth: But that which is received by Autho∣rity, are these sorts of measures, the Wine-measure is 231 Cubique Inches, and for Ale 282 Cubique-Inches or Beer; and for Drie things, as Corn 272 Inches. These Rules are undeceivable with Authority.