THE TECHNOLOGIST. [Oct. 1, 1864. 



140 REVIEWS. 



each block comes out ready to pass into the hands of the builder, 

 sculptor, or dealer, and this with much less cost and loss in waste 

 than formerly attended blasting and other powerful but rough modes of 

 extraction. The continued repetition of these several operations pro- 

 duces a terrace or step-like profile in the workings, extending from the 

 highest to the lowest of the beds worked, and thus they present 

 themselves to the view. 



Professor Phillips said such a paper as this was of the utmost 

 practical importance in connection with science. 



Professor Ansted pointed out that the Bath stone, when carried for 

 building purposes to a distance, was exposed to rapid destruction by the 

 action of the atmosphere. He attributed this to the manner in which 

 the stone was quarried. It had been observed that this did not occur 

 with the stone that was used in the immediate neighbourhood of Bath. 

 This, no doubt, was attributable to the fact that the stone was not taken 

 away from its own atmosphere, as is done. He would suggest, therefore, 

 to the quarry-owners, that all the stone to be sent to a distance should 

 be exposed to its own atmosphere for some considerable time, until it 

 had became seasoned, as it were. He believed that if this were done, 

 the stone would be as durable everywhere as it was in the immediate 

 neighbourhood of Bath. 



Utttim 



Practical Illustrations of Land and Marine Engines and 



Boilers. In Twenty Plates, Elephant Folio. By N. P. Burgh, 



Engineer. 

 a pocket-book op practical rules for the proportions of 



Modern Engines and Boilers for Land and Marine Purposes. 



By N. P. Burgh. London : E. and F. K Spon. 

 These are works calculated to be of great utility to professional men 

 and machinists. The large plates give in detail all the modern improve- 

 ments in high and low pressure engines, surface condensation, and 

 superheating, together with land and marine boilers, and prove Mr. 

 Burgh's great capabilities and excellence as a draughtsman, and judg- 

 ment in making his plates complete working drawings. 



Plates 1, 6, 7, 12, and 20, representing engines of various kinds, are 

 designed by the author from the rules given in the Pocket-Book. These 

 plates give the details of a high pressure steam-engine of 12 H.P. ; and 

 four plates illustrate the details of a marine-engine. 



