576 TRANSACTIONS OP THE AMERICAN INSTITUTE. 



by the Polynesian Islands. One of these streams moves northward along- 

 the east coast of Formosa and Japan to the chain of islands south of the 

 Gulf of Yeddo, where it has a velocitj' of about 80 miles a day. This stream 

 is called the Kuro-Siroo, and corresponds to our gulf stream. Between 

 Formosa and the Majico-Sima islands its width is about 100 miles. It ex- 

 pands until opposite the Loo-Choo and Bonin islands, where it is about 500 

 miles wide. It sets to the eastward, and its warm influence extends to the 

 northwest coast of North America, favorably affecting the climate, as the 

 gulf stream does that of the western coast of Europe. The subject of ocean 

 currents is one of profound interest. For nearly all our knowledge of th« 

 minor currents on the Atlantic coast, we are indebted to the Coast Survey, 

 under the direction of Prof. Bache. 



On motion of Dr. J. B. Rich, an unanimous vote of thanks was passed to 

 Rev. Mr. Adams, after which " Waves and Tidal Forces, and their Useful 

 Application," was selected as the subject for the next meeting on Feb- 

 ruary II th. Adjourned. 



American Institute Polytechnic AssncnTiox, ) 

 February lUh, 1864. ) 



Chairman, S. D. Tillman, Esq. ; Secretary, B. Garvey. 



New Tompion for Guns. 



Mr. Garvey presented an improved tompion ; it contains a ring of 

 India-rubber, which by the pressure of a screw in tlie center of the instru- 

 ment, was expanded so as to fit tightly into the bor<» of a gun. 



Mr. Wiard said he had seen a tompion used for artillerj'^ purposes re- 

 eembling this. 



Dr. Rowell stated tliis application of rubber by means of a screw to 

 make a tight fit has been used in a certain kind of preserve jars. 



The Chairman remarked that the same principle, without the use of rub- 

 ber, has been applied to the metallic packing of the piston of a steam en- 

 gine. By turning a screw at the center the piston, without being removed, 

 is brought to a steam-tight fit with the cylinder, 



Steam-Boiler Explosions. 



Mr. John B. Root stated tliat as far as his own knowledge as an engineer 

 extended, upright boilers with upright smoke-tubes were not so liable to 

 explode as those lying horizontally. He wished to gather facts relating to 

 this point. 



Messrs. Wiard, Dibben, Rowell, and Miller respectively cited cases of the 

 explosion of upright boilers. 



The Chairman presented the following summary of scientific news : 



Occult Poisons. 



According to the investigations of Prof. Letheby of London, nitro-ben- 

 zole and aniline, in their free state, are powerful narcotic poisons. Their 

 insidious action should be thoroughly understood by all persons engaged in 

 the manufacture of mauve, magenta, and other aniline coloring compounds. 



