^S Mechanical Philosophy. [Chap. I. 



Chappc immediately became an object of public 

 attention. Additions and alterations in his plan 

 were proposed, some of them highly advan- 

 tageous; and telegraphs of different kinds came 

 into use in various parts of the continent of Europe, 

 and in Great Britain. How great the importance 

 of this channel of intelligence is at present, and 

 how much more so it may be rendered by those 

 improvements in its construction and management 

 which we may reasonably expect to take place, 

 will readily occur to every mind. To say nothing 

 of the dispatch with which information might be 

 conveyed, by this means, in time of war, and 

 the evils of various kinds it might prevent, it may 

 hereafter become an instrument of commercial 

 communication of the highest utility, and be ren- 

 dered subservient to many valuable national pur- 

 poses*. 



The late experiments and conclusions of Dr. 

 Ilerschel, with respect to the rays of light and 

 heat, are curious, and highly interesting^. He 

 seems to have demonstrated that the ditTerept 

 prismatic colours have different degrees of tempe- 

 rature ; that radiant heat, as well as light, is not 

 only refrangible, but also subject to the laws of 

 dispersion, arising from its different refrangibility; 

 that those rays of light which have the greatest 

 illumijiating power are the yellou^ and those vvhicli 



••' Mr. Jonathnn Grout, of Massachusetts, in l/pQ, invented a 

 Telegraph on a plan which is said to be essentially ditterent froHi 

 any now in use in Europe. It has been for some time in opera- 

 tion between Boston and Martha's Vineyard, at which distance 

 (90 miles) Mr. Grout has asked a question and received an an- 

 -j»\rer in Icsi than ten minutes. 



