WEIGHTS AND MEASURES 1119 



means of the following implement, represented in fig 2112. c, c is the view of it 

 from above, or the plan ; D is a side view; E a longitudinal section, and /an oblique 

 section across. The chief part consists in a wooden groove, or chamfered slip of 

 wood, open above, and rounded on the sides. It is about 21 inches in length, about 

 as long nearly as the web is broad, therefore a little shorter than the horse-hairs in- 

 serted in it, which project about an incli beyond it at each end. They are herein 

 pressed down by elastic slips, e, of india-rubber, so that the others remain, when 

 one or more are drawn out by the ends. The ends of the grooves are flat where the 

 india-rubber spring exerts its pressure, as shown by the dotted line /. The spring 

 is formed by cutting out a double piece from the curvature of the neck of a caoutchouc 

 bottle or flask, fastening the one end of the piece by a wire staple in the groove of 

 the shuttle, whereby the other end, which alone can yield, presses upon the inlaid 

 hair. Wire staples like / (in the section E) are passed obliquely through two places 

 of the groove or gutter, to prevent the hairs from springing up in the middle of the 

 shuttle, which is suitably charged with them. The workman shoves the tool across 

 the opened warp with the one hand, seizes with the other the requisite number of 

 hairs by the projecting ends, and holds them fast while ho draws the shuttle once 

 more through the warp. The remaining hairs are retained in the groove by the 

 springs, and only those for the single decussation remain in the web, to be secured to 

 the list on either side. A weaver with this tool can turn out a length of cloth double 

 of what he could do with the mouth-shuttle. 



WEBSTERXTE. A hydrous subsulphate of alumina, found at Newhaven and 

 Brighton, in .Sussex ; at Halle ; and in several French localities. 



WEFT (Trame, Fr. ; Eintrag, Ger.) is the name of the yarns or threads which 

 run from selvage to selvage in a web. 



WEIGHXNTG- MACHINE. See BALANCE. 



WEIGHTS and MEASURES. Metrical and Imperial. The metrical system 

 originated with the government of Louis XV., who named a commission to pursue 

 the investigations necessary to decide the principles upon which such a system could 

 be carried out. An extensive series of observations were conducted during the reign 

 of Louis XVI. Under his consent the Academy of Sciences decided that all the 

 different weights, measures, and coinages should bo established accessory to certain 

 definite relations to the dimensions of the globe itself. 



Delambre and M^chain ascertained the length of the earth's meridian in the portion 

 between Dunkirk and Barcelona, and Arago and Biot that between Barcelona and 

 Formentera. The length of the meridian from the Polo to the Equator, passing 

 through Paris, was then divided into 10,000,000 parts, and one of these parts, called 

 the metre, became the basis of the new system. 



Maupertuis had, in the year 1736, measured a portion of the arc of the meridian 

 passing through the North Cape. His observations were therefore combined with the 

 others by the commission. The distance from the Equator to the Pole, which is really 

 10,000,738, was fixed at 10,000,000. This standard is, therefore, the ten-millionth 

 part of the quadrant of the terrestrial meridian ; and from the measurements and 

 calculations which were made at that period on the arc of the meridian which ex- 

 tended from Barcelona to Dunkirk, it was reckoned to be 39'371 inches of the 

 English standard yard, which contained 36 inches. Thus the French metre, which 

 is longer than the English yard by 3j inches, or more accurately by 3^f inches, is 

 the standard of all the measures and weights of France. Its decimal multiples 

 are successively denoted by the prefixes deca, hcca, kilo, &c., which signify 10, 100, 

 1000, &c., times respectively; and its decimal submultiples or fractions successively 

 by the prefixes deci, conti, milli, &c., which signify i, ^5, j-^j, &c., parts respectively. 

 The metre itself was made the unit of lineal measure and itinerary distances. 



A bar of platinum was constructed representing the length of the mtre as accu- 

 rately as possible ; and this bar, or others directly or indirectly copied from it, is the 

 standard unit of length throughout France, and in many other countries which have 

 herein followed her example. It is equal to 39'371 English inches, and is about ^ of 

 an inch longer than a pendulum vibrating seconds at the level of the sea in London. 



2114 



The metre is divided decimally downwards, into decimetres, centimetres, and milli- 

 metres (fig. 2114) ; and multiplied decimally upwards into decametres, hectometres, 

 kilometres, and myriametres ; the latter being, as is implied by its name, equal to 

 10,000 metres of the scale. 



