510 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



the railroad leading from Dublin to Dnndalk, and this system was at one 

 time so popular, that it was proposed to unite England and France by- 

 means of compressed air; but it was found that the variation of the tempera- 

 ture with every stroke of the engine, was so great, as to vary the speed 

 very perceptibly. There was also an atmospheric railroad built in England, 

 which consisted of a tube sonie three feet in diameter, running the whole 

 length of the road, and laj'ing between the rails; this tube had a slot or 

 opening on the upper part, through which came a projection from the pis- 

 ton, which was fitted to this tube. The cars being attached to this piston, 

 the air is exhausted from one end, which causes a vacuum, the air behind 

 the piston pushes it forward with great velocity; but, owing to a variety 

 of difficulties, this method, I believe, is now entirely abandoned. 



The Chairman. — This atmospheric railroad differs from the ordinary 

 roads only in its motive power; they had all the other appliances of other 

 railroads, such as double track, cars, &c. Now, when we consider the 

 cost of lajn'ng this center tube, and keeping it in repair, it will be found 

 that the usual mode of taking the power along, and using, it as it is wanted, 

 is much superior. 



Dr. Parmelee. — I believe that the time is not far distant, when coal will 

 be dispensed with for generating steam, and that petroleum will take its 

 place. In Pennsylvania, at the oil wells, they use the ^il to generate 

 the steam in their boilers, and they find that 500 pounds of petroleum will 

 do as much, in the way of fuel, as 2,000 pounds of coal, thus doing away 

 with 1,500 pounds of coal, which, on cars or steamboats, is of great impor- 

 tance. But the introduction of anything new is always attended with 

 great difficulty; we all know the prejudice there was to the use of the 

 steam fire engine, the obstacles in way of their introduction seemed almost 

 insurmountable, and we all know how valuable they are at present. 



Mr. Godwin read the following statistics of the exports of petroleum 

 from the United States, in first quarter of- the year: 



1861 60,021 galls. 



1862 1,816,262 do 



1863 9, 040, 604 do 



Exports from Boston, first quarter 186.3 933,410 galls. 



Exports from Philadelphia, first quarter 1863 1,442,642 do 



Exports from New York, first quarter 1863 6,546,731 do 



Export from Neiv York to foreign ports, from Jan. 1, 1863, to Ajyril 6, 1863. 



To Liverpool 



London 



Glasgow 



Bristol 



Falmouth, E 



Grangemouth, E. 



Cork, etc 



Havre 



Marseilles 



Bordeaux 



Cette 



Dieppe 



Antwerp 



Bremen 



Hamburg 



Rotterdam 



