CHAPTER VII. 



DEEP-SEA TEMPERATURES. 



Ocean Currents and their general Eflfects on Climate. — Determination 

 of Surface Temperatures.--Deep-sea Thermometers. — The ordinary 

 Self-registering Thermometer on Six's principle. — The MiUer- 

 Casella modification. — The Temperature Observations taken during 

 the Three Cruises of H.M.8. ' Porcupine ' in the year 1869, etc. 



Appendix A. — Surface Temperatures observed on board H.M.S. 

 'Porcupine' during the Summers of 1869 and 1870. 



Appendix 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 Eates of Eeduction of Temperature with 

 Increase of Depth at Three Stations in different Latitudes, all of 

 them on the Eastern Margin of the Atlantic Basin. 



Appendix 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 Fseroe Islands ; as ascertained by 

 Serial and by Bottom Soundings. 



Appendix E. — Intermediate Bottom Temperatures showing the Inter- 

 mixture of "Warm and Cold Currents on the Borders of the 

 Warm and Cold Areas. 



If tlie 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 same, some zones would present certain pecu- 



