On the Precipitation of Calcium Carbonate. 



39 



these observations in a consideration of the hydrographic conditions, and 

 to make what deductions were possible from the results obtained at the 

 two stations given. 



Figure 2 shows the vertical distribution of layers of different salinities 

 at the two stations in diagrammatic form. 



15 



20 



100 



200 



300 



w 



o -^00 



X 



\- 



< 500 



600 



70Q 



800 



900 



Fig. 3. — Temperature curves. 

 Continuous line = Station r. 

 Broken line = Station 2. 

 Dotted Xvat=Challenger Station No. 27.; 



The curves in figure 3 show the vertical distribution of temperatures at 

 the two stations, and also give the temperatures obtained by Challenger 

 Station No. 27 in 22° 49' N., 65° 19' W. March 28, 1873, where the depth 

 was 2,960 fathoms. It is interesting to note that the actual reading at 

 200 fathoms at the latter station, 17.22° C, agrees more closely with the 

 temperatures in the Tongue of the Ocean than that taken from the smoothed 

 curve, which was 18.17° C. 



The curves in figure 4 show the vertical distribution of salinities at the 

 two stations, and also the salinities obtained by the Michael Sars in 37° 12' 

 N., 48° 30' W., on June 25, 1910. 



From these tables and diagrams it can be seen that the surface salinity 

 increases from west to east very rapidly, 0.34 per cent in 7.5 miles, but the 

 surface temperature is fairly uniform, between 26° C. and 27° C. 



At both stations the salinity increases downwards to a maximum prob- 

 ably lying between 10 fathoms and 50 fathoms, but more rapidly at Station 

 I. so that from 10 fathoms to 50 fathoms the salinity decreases from west 

 to east. 



