522 SEC. 12. APPLIED MECHANICS. 



2178fy. Model of Twin-Screw Gun Boats. Built for 

 the Spanish Government by J. and G. Rennie, 1859. Length 

 90 ft., breadth 14 ft., draught 2 ft. 6 in. ; horse-power, 30. 



J. and G. Rennie. 



2178gp. Model of the Engines of H.M. ships Boadicea" 

 and ** Bacchante," on the compound system, of 5,250 horse- 

 power indicated, 1875 and 1876. J. and G. Rennie. 



2178gq. Model of Horizontal Marine Engines, with 

 injection condensers. Made by J. and G. Rennie, 1860. 



J. and G. Rennie. 



2178gr. Model of Reversed Horizontal Marine Screw 

 Engines. Built 1860. J. and G. Rennie. 



2178gs. Drawing, design for 60 horse-power Low 

 Pressure Condensing Disc Engines for Screw Steam- 

 ship. 



The drawing shows front, side, and back elevation and plan. 

 Section of H.M.S. "Cruiser," fitted with the disc engines, 1853. 



J. and G. Rennie. 



2178gu. Compound Surface-Condensing Marine En- 

 gines. T. Richardson and Sons, Hartlepool. 



Three drawings of marine engines of the most modern construction. 



One drawing represents engines of the largest class fitted with steam re- 

 versing gear. 



Another drawing represents engines of a more moderate size, and gives 

 the names of the vessels into which they have been fitted. 



A third drawing represents marine engines of the smaller class. 



The three drawings all represent compound surface-condensing engines. 



2178ei. Whole Model of the German ironclad ships of war 

 Kaiser " and " Deutschland." Built 1874 for the Imperial 

 German navy. 7,500 tons (displacement) ; 8,000 indicated horse- 

 power ; engines by Penn and Sons, Greenwich. 



Samuda Brothers. 



2178ej. Whole Model of the " Mahrousse," state paddle 

 steam yacht. Built for His Highness the Khedive of Egypt ; tons 

 burthen, 3,150; horse-power, 800 nominal. Samuda Brothers. 



2168. Helm Indicator for the prevention of Collisions 

 at Sea. John James Nickoll. 



This is a lantern which is hoisted under the mast-head Hght of a steamer, 

 and connected with the helm by rods or chains, and acts automatically with 

 the rudder like a tell-tale, showing a green light when she is starboarding, and 

 a red light when she is porting her helm, thereby showing the course a vessel 

 is about to steer, and before she answers her helm or deviates from her 

 course. 



