THE PROBLEMS OF THE DEEP SEA. 451 



resembles that pursued by the earth, in shape as well as in extent, 

 that, if the two paths were traced down on a quarto sheet, it would 

 not be easy to distinguish one from the other. Our earth is simply 

 the largest, while the moon is the smallest of that inner family of 

 worlds over which the sun bears special sway, nor does Mercury ex- 

 ceed the moon to so great a degree in mass and in volume as the 

 earth or Venus exceeds Mercury. Yet the moon, with her surface of 

 14,000,000 square miles, seems to be beyond a doubt a mere desert 

 waste, without air or water, exposed to alternations of heat and cold 

 which no living creature we are acquainted with could endure ; and 

 notwithstanding her position as an important member of the solar 

 system, as well as the undoubted fact that in her motions she obeys 

 the sun in preference to the earth, she has nevertheless been so far 

 coerced by the earth's influence as to be compelled to turn always the 

 same face toward her larger companion orb, so that not a ray from 

 the earth ever falls upon fully 5,000,000 square miles of the farther 

 lunar hemisphere. A waste of matter here, we might say, and a waste 

 of all the energy which is represented by the moon's motions, did we 

 not remember that we can see but a little way into the plan of Crea- 

 tion, and that what appears to us waste may in reality be an essential 

 and important part of the great scheme of Nature. Spectator. 



-+*+~ 



THE PROBLEMS OF THE DEEP SEA. 



By Peof. T. H. HUXLEY, LL. D., F. E. S. 



ON the 21st of December, 1872, H. M. S. Challenger, an eighteen- 

 gun corvette, of 2,000 tons burden, sailed from Portsmouth har- 

 bor for a three, or perhaps four, years' cruise. No man-of war ever 

 left that famous port before with so singular an equipment. Two of 

 the eighteen sixty-eight pounders of the Challenger's armament re- 

 mained to enable her to speak with effect to sea-rovers, haply devoid 

 of any respect for science, in the remote seas for which she is bound ; 

 but the main-deck was, for the most part, stripped of its warlike gear, 

 and fitted up with physical, chemical, and biological laboratories ; 

 photography had its dark cabin ; while apparatus for dredging, 

 trawling, and sounding ; for photometers and for thermometers, filled 

 the space formerly occupied by guns and gun-tackle, pistols and cut- 

 lasses. 



The crew of the Challenger match her fittings. Captain Nares, 

 his officers and men, are ready to look after the interests of hydrog- 

 raphy, work the ship, and, if need be, fight her as seamen should ; 

 while there is a staff of scientific civilians, under the general direction 



