CHAPTER, VIL 
DEEP-SEA TEMPERATURES. 
Ocean Currents and their general Effects on Climate.— Determination 
of Surface Temperatures.—Deep-sea Thermometers.—The ordinary 
Self-registering Thermometer on Six’s principle-—The Miller- 
Casella modification.—The Temperature Observations taken during 
the Three Cruises of H.M.S. ‘ Porcupine’ in the year 1869. 
AppEnpDIx A,—Surface Temperatures observed on board H.M.S. 
‘Porcupine’ during the Summers of 1869 and 1870. 
Appgenpix B.—Temperature of the Sea at different Depths near the 
Eastern Margin of the North Atlantic Basin, as ascertained by 
Serial and by Bottom Soundings. 
APPENDIX C.—Comparative Rates of Reduction of Temperature with 
Increase of Depth at Three Stations in different Latitudes, all of 
them on the Eastern Margin of the Atlantic Basin. 
AppEeNDIxX D.—Temperature of the Sea at different Depths in the 
Warm and Cold Areas lying between the North of Scotland, 
the Shetland Islands, and the Féroe Islands; as ascertained by 
Serial and Bottom Soundings. 
Appenpix E.—Intermediate Bottom Temperatures showing the Inter- 
mixture of Warm and Cold Currents on the Borders of the 
Warm and Cold Areas. 
Ir the surface of this world of ours were one 
uniform shell of dry land, other circumstances of 
its central heat, its relation in position to the sun, 
and to its investing atmospheric envelope, remaining 
the samc, some zones would present certain pecu- 
