STEAM HAMMER 



5541 



STEDMAN 



Consult Whitham's Steam Engine Design; 

 Spangler's Elements of Steam Engineering. 



Related Subjects. The following articles 

 should be read in this connection : 



Governor 

 Horse Power 

 Injector 



Steam 



Turbine Wheel 

 Watt, James 



STEAM HAMMER. The steam hammer 

 was invented by James Nasmyth in 1839, and 

 immediately revolutionized all industries in 

 which heavy forging was necessary. The Na- 

 smyth hammer, as it was originally called, was 

 raised by steam admitted into a cylinder be- 

 neath it. When raised to the required height the 

 steam was allowed to escape and the hammer- 

 head fell by force of gravity. The head might 

 weigh 100 pounds or as much as 100 tons. In 

 the modern steam hammer, steam is admitted 

 alternately above and below the hammerhead, 

 the pressure of the steam from above adding 

 to the force of the downward stroke. So per- 

 fect is the control of these mighty hammers 

 that a blow with a force of hundreds of tons 

 may be given or one so gentle as to crack a 

 nut without injuring the kernel. Electrically- 

 operated hammers are coming more and more 

 into favor, and can be made as powerful as the 

 largest steam hammers. 



STEAM 'SHIP. See SHIP. 

 STEAM SHOVEL, shuv"l, a large scoop 

 operated by steam power. The scoop, or 

 bucket, is attached to a beam which can be 

 moved in any direction and raised and lowered 

 at will, power being applied from a hoisting 

 engine. The bucket is of iron or steel, with a 

 capacity of from half a cubic yard to five cubic 

 yards. It has teeth arranged along the front 

 so as to cut into earth or loose rock. The bot- 

 tom is hung on a hinge, so that when a catch is 

 released, the load may be emptied instantly. 

 The method of operation is quite simple. The 

 dipper is lowered to the ground and driven 

 forward and upward with a powerful sweep, 

 gathering earth and rock as it goes. The beam 

 is then swung into any desired position, and the 

 shovel emptied into cars or wagons, which re- 

 move the earth. 



Commonly all the parts of a steam shovel 

 are mounted on a movable car. The great 

 steam shovels with which the Panama Canal 

 was excavated are capable of handling from 

 four to five thousand cubic yards of rock or ore 

 in a day. Steam shovels are extensively used 

 in digging and loading ore in the iron mines 

 of the Great Lakes region and for digging 

 canals and cuts. 



STEARIC ACID, steair'ik as' id, a solid, 

 fatty acid which, when combined with glycer- 

 ine, forms stearin, an important constituent of 

 fats. See STEARIN. 



STEARIN, stearin, a combination of stearic 

 acid and glycerine, is the chief ingredient in 

 mutton suet, beef tallow and certain vegetable 

 fats, such as palm oil. When crystallized, 

 stearin forms pearly, waxlike scales, having 

 neither taste nor odor, soft to the touch and 

 not greasy. It cannot be dissolved in water, 

 but is soluble in ether and hot alcohol. When 

 treated with superheated steam it is resolved 

 into its component parts glycerine and stearic 

 acid. When stearin is boiled with alkali the 

 stearic acid combines with the alkali to form 

 soap, and the glycerine is separated. Stearin is 

 prepared for practical use from beef suet, cot- 

 tonseed oil and other fats. It yields an oil em- 

 ployed in the manufacture of butterine. 



STEATITE, ste'atite, a soft rock, com- 

 posed chiefly of talc, and having a soapy or 

 greasy feel. It ranges in color from light gray 

 to almost black. Steatite is easily sawed into 

 slabs and was formerly used in the manufac- 

 ture of stoves in which wood was used for a 

 fuel. The French chalk used by tailors is made 

 from a white variety of steatite. In localities 

 having cold winters small blocks of steatite 

 are used for foot stones, because they hold the 

 heat for a long time. In New England these 

 stones are called freestones. Because of its 

 peculiar oily feel, steatite is often called soap- 

 stone. 



STED'MAN, EDMUND CLARENCE (1833-1908), 

 an American poet and critic, born in Hartford, 

 Conn. He studied at Yale, and became editor 

 of the Norwich Tribune in 1852, later was con- 

 nected with several other .papers, serving on 

 the New York Tribune and as a war corre- 

 spondent for the New York World during the 

 War of Secession. In 1869 he entered on a 

 business career as a banker and broker, and 

 retired from active life in 1900. 



But his chief interest was always in literary 

 work. The Diamond Wedding, a satire on so- 

 ciety in verse, first attracted general attention 

 to him. His Alice of Monmouth is the best 

 narrative poem called out by the War of Se- 

 cession, but perhaps the best known of his 

 verses is Pan in Wall Street. For twenty years 

 Mr. Stedman devoted himself to critical writ- 

 ings, but in his last years returned to poetry. 

 Victorian Poets and Poets oj America, his first 

 critical works, he supplemented by A Victorian 

 Anthology and An American Anthology. He 



