LINEAR OR LONG MEASURE Linear Neasure.—The standard of linear, or long measure, is the length of a pendulum that will vibrate in a vacuum, at the sea level in London, at 69° F., once in a second. Scientists have determined that such a pendu lum is nearly 39.1393 inches in length; of this is taken as a standard yard. The standard yard of the United States is a metal bar kept at Wash ington. It is identical with the Eng lish imperial yard. Subdivisions and multiples of this are shown in the fol lowing table: The mile is commonly divided into halves, fourths, eighths, etc. The fur long OA of a mile) is seldom used.
A league is 3 miles, but its length is variable, for it is, strictly speak ing, a nautical term, and should be 3 geographical miles, equal to 3.45 statute miles; but when used on land, 3 statute miles are said to be a league.
The length of a degree of latitude varies; 69.16 miles is the average length, and is that adopted by the United States Coast Survey.
Less Common Linear Measures.— Additional linear measures less com monly used are the following: 48 hair's breadths 1 inch.
3 barley corns 1 inch.
3 inches 1 palm.
4 inches 1 hand.
18 inches 1 English cubit.
21.888 inches 1 Bible cubit.
2i feet 1 military pace.
3 feet 1 common pace.
3.28 feet 1 meter.
11 feet 1 great cubit.
In biblical and other old measure ments, the term span is sometimes used, which is a length of 9 inches.
The sacred cubit of the Jews was 24.024 inches in length.
The common cubit of the Jews was 21.704 inches in length.
Horses are measured directly over the forefeet, and the standard of measure is 4 inches--called a hand.
Subdivisions of the Inch.— Tool cutters and other machinists engaged in fine metal work, scientists, revenue officers, and some others, divide the inch decimally, 1. e., into tenths, hun dredths, etc. Carpenters and mechan ics engaged in rough work divide the inch into eighths or sixteenths.
The former custom of dividing the inch into twelve parts, called lines, has gone out of use.
Following are equivalents of the decimal parts of a foot in inches: Nautical Measure.—In addition to the above a distinct table of measure ments is used by geographers and mariners as follows: 6 feet 1 fathom.
110 fathoms, or 660 feet 1 furlong.
120 fathoms 1 cable's length.
6086.7 feet 1 nautical mile.
3 nautical miles 1 league.
20 lea., or 60 naut. miles 1 degree.
360 degrees The earth's cir cumference = 24,855i miles nearly.
The nautical mile is also called the geographical mile or for brevity the knot. It is 795# feet longer than the common mile.
Cloth Measure.—Another mode of measurement formerly much used by merchants on the continent of Europe and in colonial times in this country is as follows: 2i inches 1 nail.
4 nails 1 quarter of a yd.
4 quarters 1 yard.
1 aunze yard.
Fcrreign Cloth Measure 2i quarters 1 ell Hamburg.
3 quarters 1 ell Flemish.
5 quarters 1 ell English.
6 quarters 1 ell French.
42g quarters 1 ell Scotch.
An Amsterdam ell is equal to 26.796 inches. A Trieste ell is equal to 25.284 inches.
A Brabant ell is equal to 27.116 inches.
In measuring cloth, ribbon, etc., the width is not considered, and the yard is now usually divided into halves, fourths, eighths, and sixteenths. In the United States custom house the yard is divided into tenths and hun dredths.
Scales for Linear Ileasure.—The many occasions that a standard of linear measure is required suggest the utility of having always at hand a scale from which a yardstick or other measure can be constructed. Carpenters, mechanics, and farmers frequently make it a practice to carry a jointed yardstick in the pocket. It is convenient to glue a yard measure on the edge of a carpenter's bench or a sewing table, or to indicate the di vision into inches or fractions of an inch by means of small brass brads driven in flush with the surface and rubbed to a polish with emery pa per. Sailors not infrequently tattoo a yard measure on the outer side of the left arm beginning at the point of the little finger, the subdivisions being pricked into the skin in India ink. This device will be found useful to farmers, mechanics, and others. Builders, paper hangers, and others, engaged in the building trades, find a narrow steel measure, a rod or more in length, winding up in a suitable circular case by means of a spring or crank, a very convenient contriv ance.