1870.] Geology and Paleontology. 269 



consists in introducing a small jet of hot water from theboiler into 

 the base of the blast-pipe or the exhaust part of the cylinder: 

 this jet being discharged at boiler pressure into the atmospheric 

 pressure of the exhaust passages, the greater portion of the water 

 instantly flashes into steam at atmospheric pressure, and instead 

 of the heated gases from the smoke-box, a moist vapour or fog is 

 now drawn into the cylinder behind the piston, upon the engine 

 being reversed. 



Literature. 

 " Our Iron-clad Ships ; their Qualities, Performances, and Cost ; 

 with Chapters on Turret Ships, Iron-clad Earns, &c." By E. J. 

 Keed, C.B., Chief Constructor of the Navy, &c* Space will not 

 admit of such a review here as this work deserves. The fact of 

 its coming from the pen of one so experienced in the subject will 

 at once commend it as an authority upon the matter of which it 

 treats. Its title will convey a fair idea of the contents of the 320 

 pages of which this book consists ; and we can only here state that 

 whilst this treatise on Iron-clad Ships evinces a masterly know- 

 ledge of the subject on the part of its author, the style in which, 

 it is written is perfect, approaching at times to eloquence. 



7. GEOLOOY AND PALAEONTOLOGY, 



[Including the Proceedings of the Geological Society and Notices 

 of recent Geological Works.) 



Monographs of the Palseontographical Society, Vol. XXIII. — The 

 success attending combined efforts was never more happily illus- 

 trated than in the case of the Palseontographical Society, which was 

 formed twenty-three years ago for the purpose of describing and 

 figuring British Fossils. It has published the works of twenty-six 

 palaeontologists, embracing in their monographs every division of 

 the animal kingdom found fossil in this country. Nor is it merely 

 the letter-press descriptions of fossils which it effects (though these 

 now amount to 6405 pages 4to), but it is the superior means of 

 illustration it furnishes which gives such value to the Volumes of 

 this Society. The plates now number 1006, and contain 18,991 

 figures. The volume before us contains 43 plates, some of which 

 are double size. These plates, with descriptive text, are distributed 

 to subscribers for 11. Is. per annum. 



The volumes of the Palaeontographical always contain a diverse 

 series of monographs; thus we have in this years-issue, — Fossil 

 * Johu Murray. London : 1869. 



