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LVIII. 
es THE GEOLOGICAL INVESTIGATION OF SUBMARINE 
_ ROCKS. (Puare XX.) 
By J. JOLY, M.A., B.A.L, Sc.D., F.R.S., Hon. Sec. R.D.S. 
[Read Aprit 21; Received for Publication Aprin 23; Published Jury 20, 1897.] 
_ Proressor Sows, in calling attention to the importance of inves- 
tigating the various theoretical views put forward to account for 
.the formation of coral reefs, has suggested obtaining observa- 
tional evidence of the activity or inactivity of the coral-building 
polypes at considerable depths below the surface of the sea by 
actual descent of the observer in a suitable marine observatory. 
_.. Considerations as to other possible means of investigating this 
matter have given rise to the subject-matter of this Paper. 
Not only in the particular case of the coral reef would geolo- 
gical science be enriched could we get into our hands samples of 
the rocks forming the floor of the ocean, but the attainment of this 
result, in general, would probably greatly enlarge our knowledge 
_of the geological record so far as this may be revealed by examina- 
tion of the surface-rocks of the Harth’s crust. We have only to 
examine the charts of our coasts to appreciate this fact. At very 
considerable distances from our shores, up to distances of some 
300 miles westward in the Atlantic, a rocky bottom is, in places, 
revealed by the soundings. Specimens of those rocks would be 
of great interest to the geologist. Are they volcanic, plutonic, or 
sedimentary? To add even a limited knowledge of the submerged 
to what is known of the emergent, suggests possibilities too many 
to diseuss 
i. apparatus which seeks to accomplish the object of bring- 
ing up samples of the flooring rock of the sea, where this is sufli- 
ciently free of surface-material, even from very great depths, is 
SCIEN. PROC. B.D.S., VOL, VIII., PART Y. 2P 
