Miscellaneous. 83 



Newfoundland is subject to volcanic action, it would surely be well 

 to satisfy ourselves of the true state of the case by direct experi- 

 ment ; and to adopt means for the protection of a cable against evil 

 consequences, should proof of volcanic action, either of this or any 

 more active kind, unfortunately manifest itself. 



" The determination of temperature at regular intervals from the 

 surface to extreme depths would also enable us to ascertain, with 

 somewhat greater accuracy than heretofore, the vertical limits of 

 the Gulf-stream and great tidal wave ; and the point at which the 

 waters of the ocean are influenced by the deep reflux from the Polar 

 towards the Equatorial regions *. 



" The observations comprised under the fourth head (namely, 

 density and pressure) would of course only be carried on occa-r 

 sionally and under circumstances calculated to yield the most trust- 

 worthy results. The same remark applies to the observations noted 

 under the four remaining heads f. 



" Lastly, I would suggest, in the event of the survey being carried 



* In Dr. Carpenter's Preliminary Report (Proc. Roy. Soc. Dec. 1868, 

 p. 186), and Prof. Wyville Thomson's ' Depths of the Sea,' pp. 35, 302, 

 303), very prominent allusion is made to my having, in my North- 

 Atlantic Sea-bed, adopted Sir John Herschel's and Sir James Ross's 

 doctrine of a permanent temperature of 39° in the water at great depths 

 in the ocean. In both instances the allusion is couched in terms which 

 certainly convey the impression that Drs. Carpenter and Thomson had 

 not just as unhesitatingly adopted the fallacy themselves. It is a re- 

 markable circumstance, too, that in the chapter in * The Depths of the 

 Sea ' specially devoted to " Deep-sea Temperatures " (where, if anywhere, 

 the opinion of the authors prior to 1808 on so important a point ought 

 to have been explicitly stated ), the only approach to such an opinion is 

 that which immediately succeeds a lengthy extract from my work, de- 

 scribed by Prof. Thomson as '* an excellent resume of this fallacy given by 

 Dr. Wallich." " There can be no doubt " (Prof. Thomson says) " that this 

 view, which of late (?) years has received almost universal acceptance, 

 is entirely erroneous " (op. cit. p. 304). The fact is that Prof. Thomson 

 had so unhesitatingly adopted the fallacy that, in 'The .Annals' for Aug. 

 1869 (p. 122), he said — " Though I had often wondered what could be 

 the cause, I believed in this permanent temperature of the sea thoroughly, 

 and had even suggested the particular course [for the cnxise of the 

 ' Lightning '], because it nearly coincided with the isotherm of 40^ JF. !" It 

 is right that this should be clearly understood, since my sole aim in 

 dwelling forcibly on a imifornily low temperature above the sea-bed, and 

 over the greater portion of the deep-sea area, was to show that to its 

 influence would be mainly attributable the general uniformity in the dis- 

 tribution of animal life, which has already been found to prevail over that 

 vast area. But it was obviously immaterial to my argument whether the 

 temperature was permanent at 39^^ F., or ranged from 39° to 30°, or even 

 lower (see 'The North-Atlantic Sea-bed,' pp. 104, 105). The temperatmre 

 observations taken on board the ' Bulldog ' (with which I had nothing 

 whatever to do) were unavoidably meagre and imperfect, ever}' con- 

 sideration having necessarily given place to the primary one of sounding, 

 for depth, along a given telegraph route. It was indeed deep-sea 

 research conducted under difliculties. 



t In 1868, in Prof. Wyville Thomson's ' Depths of the Sea ' (p. 62), 

 this passage occius : — " One or two other questions of the highest 

 scientific interest are to be solved by our proposed investigations. 1st. 

 The eflect of pressure upon animal life, upon rrhirh there is great misappre- 



