GAUGING. See GEOMETRY.

GAUGING-Rod, an instrument used in gauging or measuring the contents of any vessel. That usually employed is the four-foot gauging rod. It is commonly made of box, and consists of four rules, each a foot long and about three-eighths of an inch square, joined together by three brafs joints; by which means the rod is rendered four feet long when the four rules are quite opened, and but one foot when they are all folded together. On the first face of this rod, marked ed 4, are placed two diagonal lines: one for beer and the other for wine: by means of which the content of any common vessel in beer or wine gallons may be readily found, by putting the rod in at the bung hole of the vessel till it meets the intersection of the head of the vessel with the staves opposite to the bung hole. For distinction of this line, there is written thereon, beer and wine gallons. On the second face, 5, are a line of inches and the gauge-line; which is a line expressing the areas of circles, whose diameters are the correspondent inches in ale gallons. At the beginning is written, ale area. On the third face, 6, are three scales of lines; the first, at the end of which is written hog/heard, is for finding how many gallons there are in Gauging a hoghead when it is not full, lying with its axis parallel to the horizon. The second line, at the end of which is written B. L. signifying a butt lying is for the same use as that for the hoghead. The third line is to find how much liquor is wanting to fill up a butt when it is standing: at the end of it is written B. S. signifying a butt standing. In the half of the fourth face of the gauging rod, 7, there are the three scales of lines, to find the wants in a firkin, kilderkin, and barrel, lying with their areas parallel to the horizon. They are distinguished by letters F. K. B. signifying a firkin, kilderkin, and barrel.

Use of the diagonal lines on this rod. To find the content of a vessel in beer or wine gallons, put the braided end of the gauging rod into the bung hole of the cask, with the diagonal lines upwards, and thrust this braided end to the meeting of the head and flaves; then with chalk make a mark at the middle of the bung hole of the vessel, and also on the diagonal lines of the rod, right against, over one another, when the braided end is thrust home to the head and flaves: then turn the gauging rod to the other end of the vessel, and thrust the braided end home to the end, as before. Lastly, See if the mark made on the gauging rod come even with the mark made on the bung hole, when the rod was thrust to the other end; which if it be, the mark made on the diagonal lines will, on the same lines, show the whole content of the cask in beer or wine gallons.

If the mark made on the bung hole be not right against that made on the rod when you put it the other way, then right against the mark made on the bung hole make another on the diagonal line; and the division on the diagonal line between the two chalks will show the vessel's whole contents in beer or wine gallons. Thus, e. gr. if the diagonal line of the vessel be 28 inches four-tenths, its contents in beer gallons will be near 51, and in wine gallons 62.

If a vessel be open, as a half barrel, tun, or copper, and the measure from the middle of one side to the head and flaves be 38 inches, the diagonal line gives 122 beer gallons; half of which, viz. 61, is the content of the open half tub.

If you have a large vessel, as a tun or copper, and the diagonal line taken by a long rule proves 70 inches; the content of that vessel may be found thus: Every inch at the beginning end of the diagonal line call ten inches. Thus ten inches becomes 100 inches; and every tenth of a gallon call 100 gallons; and every whole gallon call 1000 gallons.

Example. At 44.8 inches on the diagonal beer line is 200 gallons; so that 4 inches 48 parts, now called 4.4 inches 8 tenths, is just two-tenths of a gallon, now called 200 gallons; so also if the diagonal line be 76 inches and 7-tenths, a close cask of such diagonal will hold 1000 beer gallons: but an open cask but half so much, viz. 500 beer gallons.

Use of the GAUGE Line. To find the content of any cylindrical vessel in ale gallons; seek the diameter of the vessel in inches, and just against it on the gauge line is the quantity of ale gallons contained in one inch deep: this multiplied by the length of the cylinder will give its content in ale gallons.

For example, suppose the length of the vessel 32.06, and the diameter of its base 25 inches; to find what is the content in ale gallons? Right against 25 inches on the gauge line is one gallon and .745 of a gallon; which multiplied by 32.06, the length, gives 55.9447 gallons for the content of the vessel.

The bung diameter of a hoghead being 25 inches, the head diameter 22 inches, and the length 32.06 inches; to find the quantity of ale gallons contained in it?—Seek 25, the bung diameter, on the line of inches, and right against it on the gauge line you will find 1.745: take one-third of it which is .580, and set it down twice; seek 22 inches in the head diameter, and against it you will find on the gauge line 1.356; one-third of which added to twice .580 gives 1.6096; which multiplied by the length 32.06, the product will be 51.63776, the content in ale gallons. Note, this operation supposes, that the aforesaid hoghead is in the figure of the middle frustum of a spheroid.

The use of the lines on the two other faces of the rod is very easy; you need only put it downright into the bung hole (if the vessel you desire to know the quantity of ale gallons contained therein be lying) to the opposite flaves; and then where the surface of the liquor cuts any one of the lines appropriated to that vessel, will be the number of gallons contained in that vessel.