114 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



fathom curve in Lit. 22 10' S., long. 37 20' W., after which 

 the depth rapidly diminished to 50 fathoms at a distance of 

 70 miles from Cape Frio. 



The opening address at Dublin, by Sir Wy ville Thomson, 

 President of the Section of Geography, after recounting in 

 detail the numerous voyages made for the purpose of inves- 

 tigating ocean depths, currents, and temperatures, proceeds 

 to give a review of his own most recent results with refer- 

 ence to the general circulation of the ocean. 



K. Mobius, in the Deutsche Revue, gives a comprehensive 

 summary of the principal results of the latest investigations 

 into the ocean and its life. The first European who, by a 

 drag-net, brought up animals from the depths of the sea was 

 Otto F. Miiller, of Denmark, 1788, and earlier. Since his day 

 the oceanic investigations have extended so as to embrace 

 the depth and topography, the bottom formations, the salts 

 and gases contained in the water, the temperatures, the cur- 

 rents, and the living organisms. Of the results of investiga- 

 tions in these departments Mobius gives a short review. 



DENSITY. 



Negretti and Zambra have contrived a new deep-sea ther- 

 mometer, described and figured in Nature. To a cylindrical 

 bulb containing mercury a tube is fitted, which is contorted 

 and constricted near the bulb, and is enlarged at the remote 

 end, from which end it is graduated. When the bulb is held 

 downward, the mercury expands as usual, but when it is re- 

 versed, the column breaks at the narrowed portion of the 

 tube, flows to the other end of this, and is there read. Hence, 

 if the thermometer be lowered with the bulb downward, and 

 reversed on attaining the desired depth, the reading on com- 

 ing to the surface will represent the temperature at the time 

 of reversal. To prevent the errors caused by pressure, it is 

 enclosed in a glass sheath. 



A very remarkable series of papers, by C. Schmidt, of Dor- 

 pat, on hydrology, is being published by the St. Petersburg 

 Academy. In the latest numbers are given many notes on 

 the waters of American lakes, and a general summary of 

 all known observations on density, etc., of oceanic waters. 

 Lake Baikal and other European seas afford interesting re- 

 sults. 



