246 High-Speed Navigation Steam Turbines. [Jan. 26 / 



It is perhaps interesting to examine possibilities ot speed that 

 might be attained in a special unarmoured cruiser, a magnified torpedo- 

 boat destroyer of light build, with scanty accommodation for her large 

 crew, but equipped with an armament of light guns and torpedoes. 

 Let us assume that her dimensions are about double those of the 30- 

 knot destroyers, or of the Viper, with plates of double the thickness, 

 and specially strengthened to correspond with the increased size and 

 speed ; length 420 feet, beam 42 feet, maximum draught 14 feet, dis- 

 placement 2800 tons, indicated horse-power 80,000. There would be 

 two tiers of water-tube express boilers ; these, the engines and coal 

 bunkers, would occupy the whole of the lower portion of the vessel, 

 the crew's quarters and armaments would be on the upper decks. There 

 would be eight propellers of 9 feet in diameter, revolving at about 

 400 revolutions per minute, and her speed would be 44 knots. She 

 could carry coal at this speed for about eight hours, and she would 

 steam at from 10 to 14 knots, with a small section of the boilers 

 and supplemental machinery more economically than other vessels 

 of similar size, and of ordinary type and power, and when required 

 all the boilers could be used, and full power exerted in about half an 

 hour. 



In the case of an Atlantic liner or a cruiser of large size, turbine 

 engines would effect a reduction in weight of machinery, and also in- 

 creased economy in fuel, tending either to a saving in coal on the one 

 hand, or, if preferred, to some increase in speed on the same coal 

 consumption per voyage. 



In conclusion, it may be remarked that in the history of en- 

 gineering progress, the laws of natural selection generally operate in 

 favour of those methods which are characterised by the greater sim- 

 plicity and greater economy, whether these advantages be great or 

 small. 



The progress in this undertaking has perhaps been slow, but many 

 difficulties were met with besides those of a mechanical nature, and, 

 as is generally the case, the success so far attained has been largely 

 due to devoted colleagues and staff, and in the marine developments 

 to the enterprising and generous financial assistance. 



My thanks are due to the officials of this Institution for the kind 

 assistance they have afforded me in the arrangement of the apparatus. 



[C. A. P.] 



