Memorandum of A. B.'s Hop-Back, No. 3, Gaged,

This memorandum will furnish the means of inching the Back, for to the drip (if any) we have only to add the area, in ale, of a circle 60 inches in diameter, ten times: then the area of a circle 64.3 inches in diameter, likewise ten times; and next the area of a circle 681 inches in diameter, ten times; again, the area of a circle 72.4 inches in diameter, is to be added ten times; and afterwards, the area of a circle 76.2 inches, ten times; which will finish the Table.

Suppose the drip in this case to be 11 gallons by measure, wetting one inch of the dipping rod, at the constant dipping place; then one inch must be subtracted from each apparent depth by the rod, for the true depth, the following notice being conspicuously affixed to the Back near the dipping place.

The letters here employed, signify Jack-Back: and the figures denote that in this Back, which is

Number three, an inch is to be deducted from each depth given by the rod, for the true depth; and thus the whole depth, instead of 50 inches, will be reduced to 49 inches. We shall not here exhibit the Dimension Book for this Back, since the manner of entry must by this time be perfectly familiar to the reader: we shall, however, subjoin a portion of the Table, deeming ten or twelve inches sufficient for illustration, as the process may be continued at pleasure, by mere addition, for the whole depth of the Back.

A. B.'s HoP-BACK, No. 3, TABLED.

PROBLEM IX.

To Gage and Inch an Oval Hop-Tun.

The method of gaging an oval Tun is in all respects the same as that employed for a round Tun, except that, instead of cross diameters, we take the transverse and conjugate axes of the oval, and find a mean proportional between each pair, thus reducing the oval to a circle. For in the Table of the Areas of Circles in Ale Gallons, against each mean proportional, will be found the area of a circle precisely equal to the area of the oval at the depth where the transverse and conjugate axes, giving the proportional, were taken.

To enlarge further on this problem would be a waste of time, since the subject has been amply discussed in the MENSURATION.

We shall, therefore, only subjoin the form of a memorandum for a cylindroidal Back; and for a Back with similar, but unequal, ovals for the bottom and top

Memorandum of A. B.'s Oval Hop-Back Gaged, 10 May, 1820.

Whole Depth Mean Length Mean Breadth Mean Proportional

68.5 inches 108 inches 75 inches 90 inches

Hence the mean area of this Back, is 22.56 ale

gallons, nearly, as may be seen on entering the Table of Circular Areas for Ale, with 90 inches as diameter.

Memorandum of A. B.'s Oval Tapering Back, Gaged, 10 May, 1820.

To Gage and Tenth a Cooler.

Coolers are generally oblong flat vessels, with perpendicular sides, seldom exceeding 8 or 10 inches in depth, because their use being to receive the wort hot from the Coppers, for the purpose of cooling, it is material to expose as great a surface as possible to the atmosphere.

METHOD OF GAGING A RECTANGULAR COOLER.

Take the length and breadth crossing each other in the middle. Then cause water or other liquid to be admitted to cover the bottom of the Cooler, an inch or more in the ebbest part; and chuse a constant dipping place.

Next, put on a pair of pattens, and walk over the Cooler, taking dips in several parts of it, and noting them in a memorandum. These dips are to be regulated in such manner as that with the least labour the whole Cooler may have been visited, and the last dip taken near the constant dipping place. Then divide the sum of all the depths, by the number of dips, and the quotient will be the mean depth.

Lastly, dip at the constant dipping place, and compare the depth here found, with the mean depth. If this dip be less than the mean dip, the defect is

apparent depth at the

always to be added to the dipping place, but if greater, the excess is always to be subtracted.

This DEFECT or EXCESS must be legibly written on a post or beam, as near as possible to the constant dipping place.

Suppose first, we have 7 tenths deficient, that is, the dip taken at the dipping place is 7 tenths less than the mean depth; then the mark on the post or beam will be,

[ C. No. 1, + 00·7 ]

This expression signifies that Cooler, No. 1, gives 7 tenths too little for depth at the dipping place.

Suppose next, we have three tenths more on the dip at the constant dipping place, than the mean depth, and it will be,