420 



Messrs. Carpenter, Jeffreys, and Thomson [Nov. 18, 



reached was 1476 fathoms (Station 21). In this last-mentioned dredging 

 we got several living Mollusca and other animals, a stalk-eyed Crustacean 

 with two prominent and unusually large eyes, and a Holothurian of a lilac 

 colour. The bottom at the greater depths consisted of a fine clayey mud, 

 which varied in colour (in some cases being brownish, in others yellow, 

 cream-colour, or drab, and occasionally greyish), and invariably having a 

 greater or less admixture of pebbles, gravel, and sand. The upper layer 

 formed a flocculent mass, which appeared to be animal matter in a state 

 of partial decomposition. This was in all probability derived from the 

 countless multitude of Salpce, oceanic Hydrozoa, Pteropods, and other 

 gelatinous animals, which literally covered the surface of the sea and filled 

 our towing-net directly it was dipped overboard, and of which the remains 

 must fall to the bottom after death. Such organisms doubtless afford a 

 vast store of nutriment to the inhabitants of the deep. 



35. Dredging in such deep water is not accomplished without difficulty. 

 The dredge must be unusually heavy, to overcome the resistance to its sink- 

 ing occasioned by the friction of the immense length of dredge-line paid out ; 

 and when it reaches the bottom, it sinks by its own weight into the mud, 

 like an anchor. This would give only the same result as the cup-lead 

 or any sounding-machine, but on a larger scale ; and it would tell us very 

 little about the Fauna. Further, if by the drift-way of the vessel, or by a 

 few turns of the engine now and then, we are enabled to scrape the surface 

 of the sea-bed, the dredge gets choked up with the flocculent mass above 

 described. The fertile ingenuity of our experienced and excellent Com- 

 mander devised a method which was a great improvement in deep-sea 

 dredging, and which enabled us to obtain at least a sample of the sub- 

 stratum. This consisted in attaching to the rope two iron weights, each 

 of 100 lbs., at a distance of 300 or 400 fathoms from the dredge (when 

 the depth exceeded 1200 fathoms), so as to dredge from the weights 

 instead of from the ship ; the angle thus made caused the blade of the 

 dredge to lie in its proper position. This method, in fact, reduced the 

 working depth, by the distance of these weights from the vessel, to the 

 easy and manageable limit of 300 or 400 fathoms. Another contrivance 

 was to fasten the bag to the dredge in such a way that when it was hauled 

 in, it could be unlaced, emptied, and afterwards washed quite clean. By 

 this mode we were assured that the specimens really came from the place 

 where each dredging was made. We tried on this and other occasions a 

 contrivance devised by Mr. Easton, the eminent engineer, consisting of 

 gutta-percha valves closing inwards in a wedge-like form, which were fitted 

 to the mouth of the dredge. The object was to retain the contents of the 

 dredge while it was being hauled in ; as we had found by frequent and dis- 

 appointing experience that a large portion of the contents generally escape 

 through the mouth during this part of the dredging operation. This 

 contrivance, though theoretically admirable, was found not to answer in 

 practice, because the mouth of the dredge was so closed by the valves that 



