Page:The New International Encyclopædia 1st ed. v. 03.djvu/194

* BLASTING. 164 BLATCHXEY. removed by a succession of notable mine-blasts. The largest of these blasts was made in May, 1894. A tunnel 3X4 feet in cross-section and 80 feet long was driven into the face of the cliff and enlarged at its inner end into a 6 X 6 XG- foot chamber. This chamber was filled with 12 tons of second-grade dynamite, the tunnel packed with loose rock, and closed with a brick masonry wall. The firing of the blast removed about 78,000 cubic yards of rock. To break down the face of a quarry at South Bethlehem, X. Y., in 1889, 50 vertical holes 30 feet deep and 7 feet apart were driven near the edge of the cliff, and charged with 40 pounds of draamite each. This blast displaced between 20,000 and 25,000 tons of rock. In a similar blast at Crarae Quarry in Arg>ilshire, Scotland, in 1880, a blast of U'OOO pounds of powder dislodged 60,000 tons of gran- ite rock. To secure a large quantity of rock for building a dam near Teller, Colo., a granite mound kno%Ti as Vesuvius Butte was blown up on December 18, 1899. A horizontal tunnel, with several angles to prevent the blowing out of the blast, was driven into the side of the butte near its bottom until the inner end was about at the centre of the butte. From the end of this tun- nel a horizontal tunnel 70 feet long was driven to the right and to the left, so that the whole excavation formed a T-shaped tunnel. The ends of the cross-arm of the T were packed with some 32,000 pounds of black powder and the remaining space filled with rock and earth. The main tun- nel was also packed with earth, with green tim- ber bulkheads placed at each angle. This blast was fired by electricity, and its explosion opened up a crater 72 feet deep and 150 feet in diameter, and broke up 110,000 cubic yards of rock. By far the largest blast ever made was fired in con- nection with the removal of Hell Gate Rock in the East River at New York in 1876. This rock had an area of about 9 acres, and to remove it 24 longitudinal and 40 transverse galleries or tun- nels, with their faces pierced with 12,501 holes 3 inches in diameter and 9 feet deep, were exca- vated in its interior. Into each drill-hole was inserted a rack-a-rock cartridge, and then a dy- namite cartridge, in all 240,399 pounds of rack- a-rock and 42,331 pounds of dynamite, and then water was admitted to the mine. The blast was fired by electricity, and removed 270.717 cubic yards of rock, while about 80,000 cubic yards of rock had been taken out in excavating the gal- leries. Surface blasting is possible only with high explosives, sich as nitroglycerin, dynamite, or gimcotton, which explode by detonation so sud- denly that the shock is transmitted with shatter- ing effect to the rock with which it is in contact. Gunpowder, when fired in an unconfined space, explodes so slowly that its force is expended through the air without producing any effective local shock. Surface blasting has been exten- sively used in removing reefs and similar obstruc- tions to navigation in Long Island Sound. Small- shot submarine blasting is frequently used for similar work, and the method is well illustrated by the following typical example. In remov- ing a submarine ledge in Oswego (X. Y. ) Har- bor in 1893, a drill-scow 82 X 26 X 6Vo feet was employed, along one side of which was a track carrying two movable drill-frames. Each drill- frame carried a percussion drill operated by steam, the drill-rod of which descended down tlie side of the scow. The holes were drilled 5 feet apart in rows of 14 holes to a depth of from 4 feet to 7 feet, and charged with 2 X 18-inch dynamite cartridges, weighing 2% poiuids, and containing 75 per cent, dynamite. The entire 14 holes were fired by electricity in one blast. In charging the drill-holes with explosives for blasting, the method now in use is to employ the explosive in the form of cylindrical cartridges. Formerly, and more particularly in case gun- powder was used, the explosive was j)laced in the hole in powdered form. All high explosives are now fired by electricity, several holes being fired simultaneously. As each hole is charged, a de- tonator or cap with two wires attached is in- serted in the top of the cartridge. The first wire of the first hole runs to the battery, as does the last wire, the other wire being used to connect several holes with each other. When the first and last wires are secured to the poles of the fir- ing-battery- or frictional electric machine and the current passed through them, the detonators or caps in the cartridges are exploded by the cur- rent, and in turn cause the explosion of the cart- ridge. Vhere a time-fuse is used, the end of this fuse is inserted into the detonator, which is itself inserted into the top of the cartridge; the outer end of the fuse is then lighted and the fire fol- lows the fuse until the detonator is reached and exploded, thus causing the explosion of the cart- ridge. For a comprehensive discussion of blast- ing operations, consult: Drinker, Tunneling, Ijxplosive Compounds and Rock Drills (Xew York, 1874) : for a more concise description, in Prelini, Tunneling (Xew York, 1901). See Ex- plosives. BLASTOIDEA. See Pentbemites. BLA'TANT BEAST, The (archaic blate, to l)abble, prate; cf. Engl, bleat, the cry of sheep). Spenser's personification of slander, in the Faerie Queene. It is temporarily muzzled by Artegal, and Calidore afterwards seeks its death. BLATCH'FORD, Samuel (1820-03). An American jurist. He was born in Xew York City, graduated at Columbia in 1837, and was admitted to the bar in 1842. In 1845 he went to Auburn and joined William H. Seward and Christopher Jlorgan as a law i)artner, but re- turned to Xew York in 1854, and was appointed district judge of the United States Court for the Southern District of Xew York in 18G7, and cir- cuit judge for the Second Circuit in 1878. In 1882 President Arthur appointed him an asso- ciate judge of the United States Supreme Court. BLATCH'LEY, Willis Stanley (1859—). An American naturalist and geologist, born at X'orth Madison, Conn. He graduated at Indiana State University in 1887; was a member of Sco- ville's scientific expedition to Mexico (1891), of the .Arkansas Geological Suri'ey (1889-90), and of the United States Fish Commission (1893). In 1894 he became State Geologist of Indiana. The following are some of his publications: Gleanings from Xature (1899); "How Plant? and Animals Spend the Winter," in Popular .S'ci- cnce Monthly (Xew York, 1897) ; "Some Indiana Acrididae," in Canadian Entomologg (London, 1891) ; "Locustidie and Blattidff of Indiana," in Proceedings of the Indiana Academy of Science (Brookvifle, Ind., 1892); and numerous con- tributions as editor of Vols. XX. -XXV. of the Annual lieports, Department of Geology and