No. 7.] CARPENTER — DEEP-SEA LIFE. 421 



opened up in so far as the iron deposits are concerned, but the 

 coal is fully opened, and its adaptation to iron-smeitiu<]; ascer- 

 tained. Both have now attracted the attention of capitalist;^, 

 and unless mismanagement or abnormal political or commercial 

 conditions prevent, will ere long become great and important 

 sources of wealth and centres of manufacturing industry, and 

 will render Canada independent of the rest of the world in so 

 far as its supplies of iron are concerned. It would be impossible 

 to convey any idea of Dr. Harrington's lleport by extracts, and, 

 te quote references to particular districts might appear invidious. 

 All interested in the development of our mineral resources 

 should study it for themselveF=. j. w. D. 



ON THE CONDITIONS WHICH DETERMINE THE 

 PRESENCE OR ABSENCE OF ANIMAL LIFE 

 ON THE DEEP-SEA BOTTOM.* 



By Dr. W. B. Carpexter, F.R.S. 



The foundation of Geological Science must be based upon a 

 study of the changes at present going on upon the surface of the 

 earth, including the depths of the sea. This is the distinctive 

 feature of modern Geology. Until recently nothing was really 

 known of the depths of the ocean ; but, owing to improved 

 methods of sounding, the bottom of the sea has been reached 

 in so many places, that we may feel tolerably sure that its depth- 

 seldom exceeds four miles. Recent statements rejrardinor an 

 extraordinary depth off the coast of Japan, are most probably due 

 to an error similar to that which formerly represented the Straits 

 of Gibraltar as unfathomable — an error caused by the carrying 

 out of the sounding-line in a strong surface-current. The general 

 depth of the Atlantic does not exceed three miles, though, as an 

 exception, the ''Challenger" has recently attained 3800 fathoms 

 in a hole 100 miles north of St. Thomas. As an additional proof 

 that this was a true sounding, both the protected thermometers 

 came up crushed. 



The temperature of deep water has only lately been ascertained 

 with accuracy, the earlier attempts having been vitiated by the 

 error arising from pressure. Of the older attempts to ascertain 

 the temperature of the deep strata, that devised by Lenz in the 



* (reological Magazine. — The substance of a lecture delivered be- 

 fore the Greologists' Association, on December 4th, 1874. 



Vol. YII. cc Xo. 7. 



