EQUIPMENT. 



23 



a laboratory on shore at some point near deep water, carryino- 

 the bottles to the laboratory for analysis. 



A small chemical laboratory was fitted up on board the 

 " Challenger," where the elements of the chemistry and physics 



Tt' ,.i 





Fig. 17. — Sigsbee's 

 Water-Cup. (Sigs- 

 bee.) 



Fig. 18. — SBction of 

 Sigsbee's Water-Cup. 

 (Sigsbee.) 



Fig. 19. — Mode of 

 Attaehmant of 

 Thermometer and 

 Cups. (Sigsbee.) 



OHll 



Fig. 20. — Miller- 

 Casella Thermom- 

 eter in Protecting 

 Case, with Sigs- 

 bee's Attach- 

 ment. (Sigsbee. ) 



of the water at the bottom of the oceans were worked out by 

 Mr. Buchanan, the chemist of that expedition. From his an- 

 alyses it appears that the amount of carbonic acid present in 

 water taken from the bottom is much greater than in surface 

 water, and that the amount of oxygen gas may be somev/hat 

 larger than at the surface. 



The apparatus used for bringing up the animals living at 

 great depths is very simple. Until recently, the dredge first 

 used by a Danish naturalist, 0. F. Miiller in the last century, 



