422 SEC. 12. APPLIED MECHANICS. 



8,164 tons. Built, 1868. 1,100 horse-power, nominal. Lent 

 by Humphrys and Tennant, Engineers, Deptford. 



South Kensington Museum. 



Note. The engines of H.M.S. "Monarch" were designed and built in 1868 

 by the lenders of the model. Their indicated horse-power is 6,600 horses. 

 The engines make 60 revolutions per minute, and are on the direct-acting 

 principle, with return connecting rods, and have surface condensers. There 

 are four piston rods to each engine piston. The cylinders are 120 inches 

 in diameter, having a stroke of 4 feet 6 inches. 



The condensers are of wrought iron, their tops being of cast brass. They 

 can be used either as surface or jet condensers. They contain 17,264 copper 

 tubes, each 6 feet long, giving large condensing surface per nominal horse- 

 power. The water is driven through the condensers passing outside the tubes, 

 by a reciprocating pump, the inlet and outlet pipes being of ample diameter. 



The cylinders of the engines are steam jacketed. 



The crank shaft is 22 inches in diameter, and the propeller shaft 18 inches. 



The starting, stopping, and reversing gear is placed on a central platform 

 between the cylinders and condensers of the engines. 



The crossheads to piston rods are forged solid; their guides have very 

 large surfaces ; they are easily adjusted. 



The boilers are tubular, having brass tubes. They contain 21,000 square 

 feet of heating surface, and about 770 square feet of grate surface. 



The ship's propeller is a two-bladed Griffith screw, of gun-metal ; 23 feet 

 6 inches diameter, with adjustable pitch from 23 feet 6 inches to 28 feet 

 6 inches. The propeller weighs 22 torts. 



2153. Model, on a scale of 1 inch to 1 foot, of the horizontal 

 condensing screw engines of H.M.'s turret ship " Prince Albert," 

 2,529 tons, Built, 1860. 500 horse-power, nominal. Humphrys 

 and Tennant, Engineers, Deptford. South Kensington Museum. 



Note. The "Prince Albert " was built in 1864 by Messrs. Samuda. She 

 is an armour-plated turret ship, 240 ft. in length, 48 ft. beam, 25 ft. 3 inches 

 in depth. She is driven by engines, of which the model is a representation, 

 and fitted with a four-bladed screw propeller. 



2153a. Whole Model, an iron floating dock built for the 

 French Government by Messrs. Randolph, Elder, and Co., Glas- 

 gow, Port Saigon, Cochin China. John Elder and Co. 



Dimensions of the dock: Length 300 feet, breadth 94 feet, depth 42 feet. 

 Weight of dock, 2,800 tons. 



The dock will lift a ship of 4,800 tons weight, drawing 27 feet of water. 



2153b. Three Drawings of compound marine steam-engines, 

 constructed and fitted on board H.M.S. " Constance" in 1863, by 

 Messrs. Randolph, Elder, and Co., Glasgow. John Elder and Co. 



They were the first compound engines fitted in any of H.M. ships, and have 

 two 60 inch cylinders, four 78 inch cylinders, and a stroke of 3 feet 3 inches, 

 and have surface condensers. 



No. 1, plan, looking forward. 



No. 2, cross sectional elevation, looking forward. 



No. 3, cross sectional elevation, looking astern. 



2153c. Model of the bridges used on board H.M.S. " Orontes " 

 for carrying and launching ships' life-boats. John White. 



