VII. NAVAL ARCHITECTURE, ETC. 425 



2159h. Drawing of the " London Engineer," 70 horse- 

 power, a vessel fitted with a central paddle wheel, and air-tight 

 paddle case, in the year 1818, intended to run to Margate. The 

 scheme did not succeed, owing to the difficulty of keeping a suffi- 

 cient supply of air in the paddle case to keep down the level of the 

 water. Mauds lay, Sons, and field, Engineers, Lambeth. 



2160. Model of the engines of the paddle-wheel steamer 

 " Helen McGregor," of Liverpool. 



Designed in 1843 by G-. Forrester & Co., Engineers. G. For- 

 rester & Co., Liverpool. South Kensington Museum. 



Note. This engine has two inverted steam cylinders driving one crank on 

 paddle shaft, and a very long stroke. It occupies but little hull space. The 

 engine is a condensing low-pressure engine, and is said to be still at work, 

 1873. 



^ 



2161. Model of a paddle marine engine, designed by J. Scott 

 Russell, F.R.S. ; having three oscillating cylinders, all connected to 

 one crank on the paddle shaft. One of the cylinders is vertical, 

 the other two are inclined inwards at about 45. J. Scott Russell, 

 F.R.S. South Kensington Museum. 



2162. Drawing, coloured, of a patented multi-flue marine 

 boiler for high pressure ; by Messrs. R. & W. Hawthorn, 1868. 

 Scale, i inch to 1 foot. R. & W. Hawthorn, Engineers, New- 

 castle-on-Tyne. South Kensington Museum. 



Note. The drawing shows a front view and cross section of the boiler. 

 Longitudinal through sections and cross sections. A sectional plan. 



2163. Model of a set of patent high-pressure marine tubular 

 steam boilers; designed for the continuous use of fresh water. 

 William Gray, Dawlish. South Kensington Museum. 



Note. These boilers possess the following arrangements : They are fired 

 from each end, the furnaces having special air-flues designed to assist in the 

 combustion and the consumption of smoke. They are multi-tube boilers, 

 having steam superheaters, and over all large tanks to contain fresh water, 

 which supply the boilers with heated feed water. The working pressure is 

 100 Ib. per square inch. 



2164. Drawing. Sections of Gray's patent high-pressure 

 marine steam boilers, showing arrangement of the tubes, steam 

 superheater, water heater, and flues. Scale, \ inch to 1 foot. 

 W. Gray, Dawlish. South Kensington Museum. 



2165. Drawing, on a f-inch to 1-foot scale, of an improved 

 marine tubular steam boiler ; for high pressure. Designed and 

 patented by Messrs. J. and F. Howard. Made by the Barrow 

 Shipbuilding Co., Barrow-in-Furness. J. and F. Howard, 

 Engineers, Bedford. South Kensington Museum. 



Note. The drawing shows a front view of the boiler, side elevation, longi- 

 tudinal through section ; and a section through tube plates showing method 

 of coning joints, on a quarter full-size scale. 



