Oct. 1, 1864.] THE TECHNOLOGIST. 



REVIEWS. 141 



Plate 5 gives four views of a Cornish boiler of the usual kind, in 

 which the mode of setting is clearly and practically shown. 



Plates 13 and 14 give the details of a paddle-wheel and feathering- 

 wheel, details which we have never before seen illustrated ; and 

 Plate 15, Griffith's patent screw propeller, contains five views on an un- 

 usually large scale. Messrs. Eavenhill, Salkeld, and Co. contribute a 

 plate showing the arrangement of a pair of marine steam-engines, of 

 900 H.P., for the Imperial Ottoman iron-clad frigate Sultan Mahmoud. 



Plate 17 is a drawing of a marine boiler with superheating tubes, 

 which may be studied with great advantage for the information it 

 affords in putting the boiler-plates together, fitting the stays, &c. 



Plates 18 and 19 are examples of ordinary and surface condensers, 

 with air-valves. 



The Pocket-Book contains nearly 1,000 rules, chiefly for designing, 

 constructing, and erecting land and marine engines and boilers. It 

 commences with the high pressure engine, the latest and best known 

 examples of which are described ; the rules connected with this, 217 in 

 number, are ranged under twenty-two sections. Then follows a descrip- 

 tion of the condensing beam engine, and mode of working the valves, 

 with about 100 rules adapted to the subject. We then come to a descrip- 

 tion of the marine screw engines made by the most eminent firms in 

 London ; and there are nearly 300 rules, divided into forty-seven sec- 

 tions, adapted to the common and equilibrium slide valves, practical 

 arrangement of the valves in the condenser, for the air-pump &c, &c, 

 with many valuable improvements suggested by the author. Passing 

 next to oscillating engines, we have upwards of 100 rules, with tables of 

 cylinder proportions, starting gear for all kinds of engines, surface con- 

 densation, &c. We have then a large number of valuable rules for land 

 and marine boilers, including safety valves and superheating. The work 

 concludes with a collection of miscellaneous rules for general application, 

 with tables of proportions of works, bolts, nuts, copper pipes, &c, and 

 areas and circumferences ; all of great practical utility for ready refer- 

 ence. We have thus given a sufficient outline of the research and mecha- 

 nical knowledge condensed in a small compass calculated to be always 

 available for consultation on dubious points, and must congratulate the 

 author on the result of his arduous labours, which can only be fully 

 appreciated by the practical man. His work will, there is little doubt, 

 be looked up to as a standing authority among machinists and mecha- 

 nical engineers. 



Tables for comparing British with Metric Measures and 



Weights. By C. H. Dowling, C.E. Lockwood and Co. 

 We have in this work a long series of most valuable tables, in which the 

 British standard measures and weights are compared with those of the 

 metric system at present in use on the Continent. Through various foreign 

 treaties our trade and commerce with continental countries are rapidly 



