PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 301 



In the mount ime, and soon after, similar works were completed in otlier 

 States, amountinj^' in tlio agg-regate to about two thousand miles. Tho 

 Grand Erie Canal was subsequently enlarged to about twice its original 

 capacity. Its numerous aqueducts, double locks, viaducts, and bridges, of 

 cut stone, have never been equalled by any similar structures. This mag- 

 nilicent work, with its branches forming a water communication for boata 

 extending within this State over 1,000 miles, must be regarded as one of 

 the modem wonders of the Avorld. 



R.\ILROADS. 



The excitement which followed the first opening of the Eric Canal had 

 scarcely subsided, when public attention was directed to a more expedi- 

 tious mode of transportation. 



Railroad companies were chartered in several States in 1828; two years 

 before! the English railway from Manchester to Liverpool was opened, 

 twelve miles of the Baltimore and Ohio Railremd was completed and in use. 

 In 1831 the railway between Albany and Schenectady was in successful 

 operation. The tide of public sentiment was by this time strongly in favor 

 of the new mode of travelling. Railways were projected in every direc- 

 tion, and completed with astonishiug rapidity. The invention of tlie T 

 rail by Robert L. Stevens, of Hoboken, who devised the form of rollers for 

 making it, and the adoption of the American plan of cross-ties, gave the 

 railway tlie essential qualities of stability, smoothness, and security. In 

 1860 the railroads of the United States exceeded in extent the combined 

 roads of the Old World. The demand for Civil Engineers, in the prosecu- 

 tion of the works already- mentioned, has been incessant from the beginning*. 

 It is needless to add that our Colleges have furnished but a small portion 

 of ihe suppl3\ Some of the most eminent of this profession were educated 

 at West Point; but, in general, the Engineers who have acquired the great- 

 est celebrity in planning and superintending important works, attained 

 their skill while acting previously as assistants on similar structures. 



THE ELECTRIC TELEGRAPH. 



By the side of nearly all railways, and on many common roads, may be 

 seen the wires of either the writing telegraph of Morse, or the printing 

 telegraph of House, making an aggregate length far exceeding in extent 

 the combined telegraphic lines of Europe and Asia. 



COAL MINES. 



The development of the natural resources of our country, forms another 

 interesting chapter in the history of the period under consideration. The 

 supply of wood from the native forests had scarcely began to diminish, 

 when it was discovered that hard coal could be used as a fuel, by means 

 of fire places and stoves especially adapted for it. The first cargo of coal 

 365 tons, was sent to Philadelphia in 1820 ; tho amount consumed in 1856 

 was 3,000,000 of tons. A survey of the coal fields of the United States 

 has revealed the astonishing fact, that in extent they far excefid the sum 

 total of all other coal formations, as far as known, on the face of the globe. 



METALLIC ORES. 



Not less remarkable are the metalliferous deposits thus far discovered. 

 Iron ores of superior quality arc widely diffused, especially on the eastex'n 



