480 POPULAR LECTURES AND ADDRESSES. 



over estimate. It is certainly of very great im- 

 portance indeed to this country, which depends so 

 much on shipbuilding, and the prosperity of which 

 is so much influenced by the success of its ship- 

 builders, to find the shapes of ships best suited for 

 different kinds of work ships of war, swift ships 

 for carrying mails and passengers, and goods 

 carriers. I may mention also that one of our 

 great shipbuilding firms on the Clyde, the Dennys, 

 feeling the importance of experiments of this kind, 

 have themselves made a tank for experimental 

 purposes on the same plan as Mr. Froude's tank 

 at Torquay ; and Mr. Purvis, who, when a young 

 man, was one of Mr. Froude's assistants, is taking 

 charge of that work. The Dennys are going 

 through, with their own ships, the series of ex- 

 periments which Mr. Froude found so useful, and 

 which the Admiralty now find so useful, in regard 

 to the design of ships ; and as the outcome of all 

 this work a ship can now be confidently designed 

 to go at a certain speed, to carry a certain weight, 

 and to require a certain amount of horse-power 

 from the engine. 



