772 KANSAS CITY REVIEW OF SCIENCE. 



der the direction of Professor S. F. Baird, U. S. Commissioner of Fish and Fish- 

 eries, and is an exhaustive descriptive and statistical illustrated report of the 

 vi'hole subject, beginning with the oyster industry of the maritime provinces of 

 Canada and taking in the entire Atlantic coast, as well as those of the Gulf of 

 Mexico and the Pacific Ocean; closing with the Natural History of the Oyster, 

 a glossary of terms and general summary. 



Professor IngersoU has evidently devoted a great deal of time and careful 

 investigation to the preparation of this report, and has certainly collected a vast 

 and instructive array of facts on a subject of which most persons are utterly igno; 

 rant; for which he is entitled to great credit. 



OTHER PUBLICATIONS RECEIVED. 



A Recalculation of the Atomic Weights, by Prof. F. W. Clarke, S. B., Uni- 

 versity of Cincinnati ; Proceedings of the Boston Society of Natural History, Vol. 

 2 1, Part II, December, 1880, to October, 1881; Financial Reform Almanac for 

 1882, London, Longmans, Green & Co.; The Palaeolithic Implements of the 

 Valley of the Delaware ; Free Trade vs. Fair Trade, Cassell, Petter & Galpin & 

 Co., 1882; Bulletin of the Essex Institute, Vol. 13, to December, 1881; Semi- 

 Annual Report of the Comptroller of the City of Kansas, Mo., December 31, 



SCIENTIFIC MISCELLANY. 



5OME RECENT IMPROVEMENTS IN THE MECHANIC ARTS. 



BY F. B. BROCK, WASHINGTON, D. C. 



A late important invention for providing armor for war ships, and one in 

 which the government of the United States is actively interested, has been de- 

 signed by a retired invalid engineer of the Navy, Mr. N. B. Clark. The House 

 Committee on Naval Affairs has already virtually decided that the new war ves- 

 sels, to be built under the funds recently appropriated by Congress, shall be con- 

 structed after Mr. Clark's plans. This invention consists essentially of a sub- 

 merged ''turtle-back," or concavo convex shield or deck, arranged below the 

 water-line of the ship, and extending from side to side and stem to stern, and 

 which forms a deflecting invulnerable shield. A shot, from any direction, neces- 

 sarily strikes this turtle-back at an angle, thereby deflecting the ball and protecting 

 the vitals of the ship. Each gun of the ship is provided with a wedge-shaped 

 deflecting shield, rounded at the back, so as to completely shield the gunner. 



