ON A PIECE OF CHALK 69 



the North- Atlantic, between Newfoundland and the Azores, 

 at a depth of more than 10,000 feet, or two miles, by the 

 help of this sounding apparatus. The specimens were sent 

 for examination to Ehrenberg of Berlin, and to Bailey of 

 West Point, and those able microscopists found that this 

 deep-sea mud was almost entirely composed of the skeletons 

 of living organisms — the greater proportion of these being 

 just like the GlobigerincE already known to occur in the 

 chalk. 



Thus far, the "Vork had been carried on simply in the 

 interests of science, but Lieut. Brooke's method of sounding 

 acquired a high commercial value, when the enterprise of 

 laying down the telegraph-cable between this country and 

 the United States was undertaken. For it became a matter 

 of immense importance to know, not only the depth of the 

 sea over the whole line along which the cable was to be laid, 

 but the exact nature of the bottom, so as to guard against 

 chances of cutting or fraying the strands of that costly rope. 

 The Admiralty consequently ordered Captain Dayman, an 

 old friend and shipmate of mine, to ascertain the depth over 

 the whole line of the cable, and to bring back specimens of 

 the bottom. In former days, such a command as this might 

 have sounded very much like one of the impossible things 

 which the young Prince in the Fairy Tales is ordered to do 

 before he can obtain the hand of the Princess. However, 

 in the months of June and July, 1857, my friend performed 

 the task assigned to him with great expedition and precision, 

 without, so far as I know, having met with any reward of 

 that kind. The specimens of Atlantic mud which he pro- 

 cured were sent to me to be examined and reported upon.^ 



1 See Appendix to Captain Dayman's Deep-sea Soundings in the 

 North Atlantic Ocean between Ireland and Newfoundland, made in 

 H.M.S. "Cyclops." Published by order of the Lords Commissioners 



