278 PROGRESS OF SCIENCE IN THE CENTURY. 



whose great Physical atlas is an immortal monument ; 

 Perthes, " the capitalist employer of cartographers " ; 

 and the critical Oscar Peschel. From these we pass 

 to living workers, such as von Kichthofen and Penck. 

 One of the great results of the nineteenth century 

 has been the development of geography as a synthetic 

 science. 



AN ILLUSTRATION OF OCEANOGRAPHY. 



The whole history of Oceanography, in its various 

 branches, has been related in great fulness by Sir 

 John Murray in his Summary of the Scientific Re- 

 sults of the Voyage of H.M.S. Challenger; we can- 

 not in a section do more than illustrate the fact of 

 its rapid development in the second half, and espe- 

 cially in the last quarter of the nineteenth century. 

 The illustration we take is the familiar but striking 

 one that within a few years we have gained a wealth 

 of information in regard to the Deep Sea, which was 

 about the middle of the century an almost unexplored 

 area. In spite of isolated hints which might have 

 been followed up earlier, it was generally believed 

 until 1860 or so, that the great depths of the ocean 

 were uninhabitable, and there was almost no knowl- 

 edge of the deposits covering the floor. A notable step 

 was taken when Surgeon-Major G. G. Wallich, 

 naturalist with Sir Leopold M'Clintock's North 

 Atlantic Expedition of 1860, showed that animals 

 lived in the abysses even below 1,000 fathoms. It 

 is interesting also to notice that one of the impulses 

 which gave Deep-Sea exploration a start was the 

 purely -practical desire to establish telegraphic com- 

 munication between the Old and New Worlds. In 

 binding these together, another new world was dis- 

 covered. 



