548 Dr. W. B. Carpenter on the [June 13, 



Lat. 72° 30' N. 



Lat. 76° 



40' N. 



Lat. 77° 



26' N. 



Long. 44° E. 





Long. 55 



°E. 



Long. 44° E. 



Depth 



Fahr. 



Depth 



°Fahr. 



Depth 



Fahr. 



to 114 feet. . . 



.40-6 



6 to 36 feet 



. ..36-5 



6 to 36 feet. . 



.36 to 35-2 







48 „ 



. . .33-8 



45 „ 



32-5 







60 „ 



. ..32-0 



60 .. 



32-5 







72 „ 



. . .30-9 



75 „ 



30'6 







90 „ . 



, . ,30-6 



90 „ .. 



30-4 



144 



.36-5 



120 „ . 



. . .29-7 



120 „ .. 



29-1 



m 



.35-6 



180 „ . 



. ..29-8 



180 „ .. 



28-8 



1234 



.34-3 











294 



.32-9 



300 „ 



. . .29-8 







360 „ . . . 



.329 







360 „ .. 



29-1 



450 



.320 











600 



.31-3 











800 „ . . . 



.29*7 











_ " The transition of the water from the higher to the lower temperature," 

 they say * c is, near the northern limit, a very rapid one, and nearly every- 

 where occurs in closest proximity to the ice, so that we were able in the 

 thickest fog to run close up to the barrier under the guidance of the ther- 

 mometer " *. 



16. Thus, then, the additional information obtained from various sources 

 since my last Report has but confirmed the representation therein given 

 (§ 82) of the relation between the Cold and the Warm stratum in the 

 water of the Ocean ; and of that relation the doctrine of an upper and an 

 under-flow propounded by Pouillet seems to give the only satisfactory 

 rationale. — The existence of such a Vertical Circulation, however, has been 

 called in question by Mr. Croll, on the ground that it is mathematically 

 demonstrable that the force to which I attribute the movement is utterly 

 inadequate to sustain it ; and he has even gone so far as to affirm that " it 

 is needless to expect that any further observations in reference to currents 

 in the ocean will in the least degree aid Dr. Carpenter's theory ; for, sup- 

 posing it were found that the waters of the ocean do circulate in some such 

 manner as he concludes — a supposition very i?nprob able — still we should be 

 obliged to refer the motion of the water to some other cause than to that 

 of differences of temperature" (Nature, Jan. 11, 1872). Now as the 

 question is one of great interest to Physical Geographers and Geologists, 

 and as I have very high authority for regarding the whole of Mr. Croll' s 

 reasoning on the subject as fallacious, I shall endeavour to show that the 

 doctrine I advocate involves no inherent improbability, and that the cor- 

 relation of such a body of observations as it is one of the chief purposes 

 of the Circumnavigation Expedition to collect may establish it on a firm 

 basis. At present I claim for it no higher character than that of a "good 

 working hypothesis" to be used as a guide in further inquiry f. 

 * G-eographische Mittheilungen, 1872, p. 70. 



t At the Meeting of the Koyal Geographical Society, held January 9, 1871, Sir 



