SCIENCE, INVENTION, DISCOVERY. 



337 



they were made by hand by forging on an 

 anvil, and great numbers of men were em- 

 ployed in the industry, there having been as 

 many as 60,000 nailers in the neighborhood 

 of Birmingham alone. It appears that as 

 early as 160(5 a patent was obtained for cutting 

 nail rods by water power, by Sir Davis Bul- 

 mer. An improvement on this was patented 

 in 1618, and a new invention in 1790, which 

 last was the first nail machine in actual use ; 

 it was patented by Thomas Clifford, and used 

 in French's factory at Wimburn, Staffordshire, 

 in 1792. Toward the close of the last cen- 

 tury many patents were obtained in the United 

 States for new machines and improvements on 

 old ones. Many of the first inventors spent 

 large sums of money on their machines, and it 

 has been estimated that it cost fully $1,000, 000 

 to bring them to the perfection attained in 

 1810, when a machine made 100 nails a min- 

 ute. The machine invented by Jesse Reed of 

 Massachusetts, about 1800, is the one which 

 first came into general use, and this, with 

 some improvements, is the one most largely 

 used to-day. In 1810, Joseph C. Dyer of 

 Boston, then a merchant in London, took out 

 patents in England for the nail machinery in- 

 vented in Massachusetts. It was at once 

 widely introduced, and large manufacturing 

 establishments were soon founded. Some 

 factories at Birmingham are now capable of 

 making over 40, 000,000 nails a week. The term 

 penny, used to indicate the size of nails, is 

 supposed to be a corruption of pound ; thus a 

 fourpenny nail was one such that 1,000 of 

 them weighed four pounds ; a tenpenny, such 

 that 1,000 weighed te'n pounds. Originally, 

 the " hundred,'* when applied to nails, meant 

 sixscore, or 120 ; consequently the thousand 

 was 1,200. In France, the greater part of the 

 nails used in carpentry-work are made of soft 

 iron wire, pointed with the hammer, and the 

 head is formed by pinching them in a toothed 

 vise. 



Nebular Hypothesis. The Nebular Hy- 

 pothesis assumes that the solar system was 

 once an enormous mass of gaseous substance. 

 Rapid rotation arising in this gaseous mass, it 

 took the form of a disc, and at last inertia 

 (popularly but erroneously called centrifugal 

 force), overcoming cohesion, whole rings and 

 fragments flew off from this disc, and by grav- 

 itation contracted into spheroid masses. As, 

 in the original mass, the velocity of the outer 

 circle of. each body thrown off is greater than 

 the inner circle, this causes each spheroid to 

 revolve on its own axis. This process goes on, 

 and the central mass continues to cool and 

 shrink until we have at last a central body 

 with a number of smaller spheroidal bodies re- 



volving around it in orbits ; the smaller, the 

 nearer they are to the central orb. Certain 

 points are assumed in this hypothesis to ex- 

 plain the distribution of matter in our solar 

 system. It is assumed that in throwing off 

 great masses from the central disc, immense 

 quantities of minute particles were also 

 thrown, which continue to revolve, in the same 

 plane with the large mass around the central 

 body. By slow degrees these minute atoms, 

 by the law of gravitation, were aggregated 

 into the mass nearest to then . These subor- 

 dinate aggregations would form with most dif- 

 ficulty nearest the large central mass, because 

 of the superior attractive force of the latter, 

 where/ore the interior planets Mercury, 

 Venus, the Earth, and Mars are smaller 

 than the two great orbs in the zone beyond 

 them. These two enormous planets, Jupiter 

 and Saturn, occupy the space where conditions 

 are most favorable to subordinate aggregations ; 

 but beyond them the gravity of aggregating 

 material becomes reduced, and so the planets 

 found in the outer zone, Uranus and Neptune, 

 are smaller than the planets of the middle 

 zone. This hypothesis was first suggested by 

 Sir William Herschel, and was adopted and 

 developed by Laplace. 



Needles. - The making of Spanish needles 

 was first taught in England by Elias Crowse, a 

 German, about the eighth year of Queen Eliza- 

 beth, and in Queen Mary's time there was a 

 negro who made fine Spanish needles in Cheap- 

 side, London. At his death the secret of fab- 

 rication was lost, and not recovered again till 

 1566. The family of Greenings, ancestors of 

 Lord Dorchester, established a needle factory 

 in Bucks a little later. German and Hunga- 

 rian steel is of best repute for needles. The 

 manufacture was greatly improved at White 

 Chapel, London ; Redditch, in Gloucestershire; 

 and Hathersage, in Derbyshire. An exhibi- 

 tion of ancient needles and needlework was 

 formed at South Kensington museum in 1873. 

 Nickel was first obtained as a metal in 

 Germany about 1751 ; but the ore had been 

 previously known to miners, who called it 

 kupfernickel, or Old Nick's copper, for the 

 reason that, though it looked like copper ore, 

 no copper could be obtained from it. Nickel, 

 when pure, is silvery white, and does not 

 oxidize or tarnish in the air. It is found in 

 many parts of the world, but the principal 

 mines are in Russia, Sweden, Germany, Aus- 

 tria, England, and Scotland, and in the states 

 of Pennsylvania and Connecticut in America. 

 Its chief use is for plating other metals, but it 

 is also used in alloys. 



Oceans, Depths of. The average depth 

 of all the oceans is from 2,000 to 3,000 



