CRANK 



540 



i- mi fear of fouling ; if also the jib is of a curved 

 i. we obtain the full benefit of the lift, while in 



the ordinary crane the form of the jib or the tie 

 interferes with the usual height of lift. 



Whenever much hoisting or heavy work has to be 

 done, steam or hydraulic power is always used ; the 

 cranes are then either stationary or portable, the 

 latter type being used whenever it is more con- 

 venient to move the crane to its work than the con- 

 verse. The stationary power cranes differ from the 

 hand ones mainly in their vastly greater power, and 

 consequently greater size and complexity of gear- 

 ing ; where steam is used there are generally two 

 direct-acting steam-cylinders, which replace the 

 two handles worked by hand. The very powerful 

 stationary cranes used in docks capable of lifting 

 50 to 75 tons are examples of this kind ; they are 

 always mounted on massive foundations, and so 

 Arranged as to sweep a whole circle. Hydraulic 

 power is very largely used in cranes for these 

 places and in great steel-works ; they are simpler 

 in construction, a good deal of gearing being done 

 away with ; the water in the operating cylinder 

 is always under great pressure, usually 700 Ib. 

 on the square inch. In the hydraulic cranes 

 originally introduced by Sir William Armstrong 

 & Co., the power given out by the hydraulic 

 cylinder is reduced by using systems of pulleys in 

 the inverse order, the lifting chain being attached 

 to the cylinder, then passing over a pulley fixed to 

 the head of the ram, then round other fixed pulleys, 

 and so up to the fixed pulley at jib end, the effect 

 being to increase the motion of the ram, and so 

 ecure very rapid lifts at the expense of using 

 more power. In one very ingenious steam -crane 

 (Morrison's) the post of the crane is hollow, and 

 forms the steam-cylinder, in which works a piston 

 with flexible piston-rod namely, the lifting chain ; 

 this form is very steady and very readily slewed. 



Portable cranes are mounted on plain railway 

 trucks, either of wood or iron. This truck carries 

 firmly attached to it a central post, the whole of 

 the rest of the crane being carried on a strong base- 

 plate capable of revolving round this post as a 

 pivot, the boiler being so placed (often standing on 

 its own feed-water tank) on this base-plate that it 

 forms a counterbalance to the weight to be lifted. 

 The boiler is always of the vertical type, and 

 "very simple in its internal arrangements of tubes 

 { see fig.), because it often has to work with very 

 dirty feed-water. The gearing is usually carried 

 by A frames bolted to the base-plate ; the engine, 

 having generally two small direct-acting steam- 

 139 



cylinders, is easily reversed ; by meant* of gearing 

 and clutches, which are operated by the man in 

 charge of the crane by hand or hx>t level*, the 

 engine can perform the following operation- : 

 ( 1 ) Lower or raise the outer end of the jib ; (2) 

 slew the crane i.e. the base-plate and all it 

 carries; (3) propel the truck along the rail-; 

 (4) hoist the loads. For the last three opera- 

 tions the gearing is generally HO arranged that 

 there are two speeds, a quid: and a slow, either 

 of which can be used, depending on the work to 

 be done. The figure shows a ^ery common type 

 of this kind, which will lift from 5 to 7 tons, 

 according to the position of the jib. For the 

 maximum load the chain end is often attached 

 to end of jib, and then round a hanging-block, 

 and so up to fixed pulley at jib end, thus doub- 

 ling pull on chain. For the same purpose as the 

 ordinary crane are used contrivances known as 

 derricks, which consist essentially of a mast or 

 tripod with a long cross-boom at the top, tied to 

 the mast by guys ; pulley-blocks attached to one 

 arm of the boom form the means of lifting. 

 They are a good deal used in America for 

 very heavy work, such as raising wrecks, bridge- 

 building, &c. They readily lend themselves for 

 use as floating-cranes, since by making the vessel 

 carrying them in watertight compartments which 

 can be filled, it is easy to counterbalance the load. 

 Electric cranes are also now in use. 



Crane, THOMAS FREDERICK, a learned folk- 

 lorist, was born in New York city, July 12, 1844. 

 He was educated at the public school and aca- 

 demy of Ithaca, New York ; and graduated at the 

 college of New Jersey (Princeton) in 1864; A.M. 

 in 1867; and Ph.D., causa honoris, in 1874. He 

 was appointed assistant- professor of Modern Lan- 



fuages in Cornell University in 1868, professor of 

 panish and Italian there in 1872, and professor of 

 Romance Languages in 1881. Professor Crane has 

 contributed a large number of articles to the North 

 American Review, International Review, Harper's 

 Magazine, Lippincott's Magazine, and The Nation 

 on folklore and the literary history and philology 

 of the Romance languages, especially during the 

 period of the middle ages. Since his article on 

 Italian folk-tales in the North American Review 

 for July 1876, he has devoted much attention to 

 the subject of the origin and diffusion of popular 

 tales, and was one of the founders of the American 

 Folklore Society (1888). Among his books are 

 Italian Popular Tales (Boston, 1885); Le Roman- 

 tisme Franqais (New York, 1887); and an edition 

 (1890), for the English Folklore Society, of the 

 !'.'< in i>li i or illustrative stories contained in the 

 sermones vulgares of Jacques de Vitre, Bishop of 

 Acre (died 1240), containing the Latin text, trans- 

 lation into English, elaborate notes on the origin 

 and diffusion of the individual stories, and an in- 

 troduction on the life of the author, and the use 

 of illustrative stories in medieval sermons, ,\.-. 

 Professor Crane's Italian Popular Tales forms. 

 from its extent, . its scientific accuracy, and the 

 wide learning of it- notes, one of the most im- 

 portant of recent contributions to storiology. 



Crane, WALTER, painter and socialist, was 

 born at Liverpool, 15th August 184"), the son of an 

 artist, Thomas Crane (1808-59). Ho lmii>clf \\;i^ 

 trained as an artist, and his earlier as well as much 

 of his later work consists of Itook-illustrations. 

 Among these may le named his series of ' Toy- 

 books^ 1869-75), 'The Baby's Opera ' (1877), and 

 'The Sirens Three,' in which last the poem as well 

 as the designs was his work. In 1862 he began to 

 exhibit paintings at the Royal Academy, showing 

 in that year ' The Lady f Shalott : ' anil he was a 

 constant contributor to the Grosvenor Gallery from 



