iq'8 



THE POPULAR SCIENCE MONTHLY 



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Fig. 2. Oceanographical Exhibit. 



1874) and the Gazelle (1874-1876) down to all the varied patterns 

 from the ships of the cable construction companies and recent deep-sea 

 expeditions, are here displayed together with sounding wires, cables, and 

 weights, sounding machines of various types — Thomson, Lucas, Sigs- 

 bee, LeBlanc and others — exhibited either by photographs and diagrams, 

 or as actual instruments. There is also a display of typical bottom 

 samples as collected by the merchant marine. 



The study of the physical and chemical conditions in the sea is 

 elucidated by a unique collection of instruments. Pressure and re- 

 versing thermometers of the Six, Chabaud, Miller-Casella, Negretti- 

 Zambra, Knudsen, Eichter and other types are shown, together with 

 instructive exhibits of the effects of pressure at great depths in the sea 

 in crushing thermometers. Scales for recording the color of the sea 

 water and apparatus for determining its transparency are exhibited 

 near the windows of the room. The apparatus used in determining 

 specific gravity and salinity is also found here ; self-closing water- 

 samplers of the Meyer, Sigsbee and Petterssen-Nansen patterns for 

 bringing up water from any desired depth without contamination from 

 other levels, areometers, pycnometers and apparatus for chlorine 

 (Knudsen) and gas (Fox) analysis. 



In an adjacent room are meteorological instruments together with 

 an exhibit of hydrographical instruments such as drift bottles, wave 

 meters, tidal registers and current meters of Aime-Irminger, Massee, 

 Arwidson, Nansen, Ekman, Petterssen bifilar and other patterns for 

 submarine exploration. 



