1869.] 



on the Scientific Exploration of the Deep Sea. 



453 



tion should have been accomplished, we did not feel justified in interfering 

 with that duty ; since we had no reason to anticipate that such exploration 

 would add any scientific results of importance to those we had already 

 obtained. After coaling and refitting at Stornoway, therefore, we pro- 

 ceeded direct to Belfast, where we landed our collections, and took our 

 leave of the ' Porcupine ' and her highly valued Captain and Officers, with 

 an earnest hope that we may again be brought into the same congenial 

 companionship and hearty cooperation in future explorations of the like 

 kind. 



GENERAL RESULTS. 

 Physics and Chemistry. 



[For this portion of the Report, Dr. Carpenter holds himself specially 

 responsible ; his Colleagues, while concurring generally in his views, 

 being desirous of reserving their liberty to dissent from some of his 

 conclusions.] 



91. Among the most important results of the 'Lightning' Expedition was 

 the discovery of the fact that two very different Submarine Climates exist 

 in the deep channel (from 500 to 600 fathoms) lying E.N.E. and W.S.W. 

 between the North of Scotland and the Faroe banks ; a minimum tempe- 

 rature of 32° being registered in some parts of this channel, whilst in 

 other parts of it, at the same depths, and with the same surface-tempera- 

 ture (never varying much from 52°) the minimum temperature registered 

 was never lower than 46°, thus showing a difference of at least 14°. 

 Though it could not be positively asserted that these minima were the 

 io^om-temperatures of the Areas in which they respectively occurred, it was 

 argued that they must almost necessarily be so : first, because it is highly 

 improbable that Sea-water at 32° should overlie water at any higher tem- 

 perature, which is specifically lighter than itself, unless the two strata 

 have a motion in different directions sufficiently rapid to be recognizable ; 

 and second, because the nature of the Animal life found on the bottom of 

 the Cold area exhibited a marked correspondence with its presumed de- 

 pression of temperature, whilst the drift of which its Sea-bed is composed 

 includes particles of distinctly Volcanic minerals, probably derived from 

 a northern source, — the Sea-bed of the Warm area, on the other 

 hand, being essentially composed of G lobifferina-mud, and supporting a 

 Fauna of a warmer temperate character. — This conclusion, it is obvious, 

 would not be invalidated by any error arising from the effect of Pressure 

 on the bulbs of the Thermometers ; since, although the actual temperatures 

 might be (as was then surmised) from 2° to 4° below the recorded tempera- 

 tures, the difference between them would remain unaffected, the pressure 

 exerting exactly the same influence at the same depth, whether the Sound- 

 ings were taken in the Cold or in the Warm area. 



92. The existence in the Cold area of a minimum temperature of 32°, 



