THE ASTRONOMICAL VIEW OF NATURE. 303 



national. 



of the pioneers of science. One of these benefits, and 

 perhaps that which to an external beholder marks the 

 greatest difference between the first and the second half 

 of the century, is the greatly increased intercourse which 

 now exists as compared with the earlier years of our cen- 

 tury. This intercourse has reacted on the domain of 2. 



Science be- 

 thought, and produced that exchange of ideas which ^o"?<' ^^^r- 



promotes more rapid progress. It hardly belongs to the 

 history of thought to analyse^ the different steps by which 

 the great change has been brought about. Still, a very 

 superficial glance will suffice to show how the work of 

 bringing about an international exchange of ideas has 

 been very characteristically divided among the three 

 nations in which we are specially interested. It was not 

 in the interest of thought, of science, or of literature, but 

 rather in that of commerce and of industry, that the 

 modern facilities of intercourse and exchange were in- 

 vented and introduced.^ We shall therefore expect to 



^ The principal dates of the in- 

 troduction of steam - engines and 

 telegraphs for facilitating communi- 

 cation are as follows : 



1802. The tug Charlotte Dundas, 

 built by Symington, was tried on 

 the Forth and Clyde Canal. 



1812. Henry Bell built tlie Comet 

 with side paddle-wheels. It ran on 

 the Clyde as a passenger steamer. 



1829. George Stephenson's Rocket 

 was tried on the Stockton and Dar- 

 lington Railroad, which had been 

 begun in 1821. In the year 1829 

 the Liverpool and Manchester Rail- 

 way was inaugurated. 



1838. The first steamboats, Sirius 

 and Great Western, crossed the 

 Atlantic. 



1833. A comprehensive system of 

 railways was planned by the French 

 and Belgian Governments. 



1835. The first German railway 

 was opened between Niirenberg and 

 Fiirth. The first electric telegraphs 

 for public use were almost simul- 

 taneously constructed in England, 

 Germany, and the United States 

 the first successful line being prob- 

 ably that constructed by Wheat- 

 stone and Cooke between 1836 and 

 1840. The first Atlantic cable was 

 begun in 1857, and after repeated 

 failures, which were in the main 

 corrected by the scientific investi- 

 gations of William Thomson (Lord 

 Kelvin), telegiaphic communication 

 with America was permanently es- 

 tablished in 1866. 



- This remark applies fully to the 

 railway system, hut scarcely to the 

 development of the electric tele- 

 graph, which was first actually used 

 for scientific purposes by Gauss and 



