GEOLOGY. 271 



average weight of a cubic foot of different coals, assumes a value of 

 no little magnitude. 



"For the purposes of steam navigation, therefore, the rank most 

 important to be considered is the fifth, in which the names of coals 

 stand in the order of their evaporative power, under given bulks. 

 This is obviously true, since, if other things be equal, the length of 

 a voyage must depend on the amount of evaporative power afforded 

 by the fuel which can be stowed in the bunkers of a steamer, always 

 of limited capacity." Hunfs Merchants' Magazine. 



COAL IN ARKANSAS. 



THE Little Rock (Arkansas) Democrat says: "We have been 

 favored by Mr. Benedict, of Conway County, with a specimen of 

 coal from the vein recently discovered in the Petitjean Mountain, at 

 the confluence of the Petitjean River with the Arkansas. This 

 specimen has much the appearance of anthracite, brilliant and quite 

 heavy. The vein from which it was taken is about five inches thick. 

 Other veins have been found in the same mountain. It is believed 

 that this deposit, being so convenient to navigation, might be worked 

 with much profit." 



ANTHRACITE COAL IN MASSACHUSETTS. 



PROFESSOR RIDGWAY, of Philadelphia, the gentleman to whom 

 was committed the survey of the coal district of Mansfield, Mass., 

 has reported to the Company. He estimates the amount of coal, on 

 about 1,500 acres of their lands, at 4,000,000 tons. It exists in five 

 beds. One vein is eight feet in thickness. He estimates the differ- 

 ence of cost between the Mansfield and Pennsylvania coal, at Boston, 

 to be $2.20 per ton. Its composition shows 94 per cent, of carbon, 

 and Prof. Ridgway states that it burns with more flame, and ignites 

 more readily, than any red-ash coal he has ever seen. 



COAL IN RHODE ISLAND. 



THE Rhode Island papers state, that, in digging a well in Bristol, a 

 bed of coal was struck about 14 feet below the surface of the ground, 

 and that it has been penetrated for 12 feet without reaching the bot- 

 tom of the ledge. The coal has been tried and found to burn freely, 

 without leaving any cinders, and its ashes are of a grayish color. It 

 has not yet been examined by any scientific miner, but the indications 

 are, that the bed extends for a considerable distance. Lumps of 

 from 300 to 500 pounds in weight have been taken out, which are 

 considered as good as the Pennsylvania coal. 



THE COAL FORMATION OF AMERICA. 



THE coal regions of America are, from the explorations which have 

 thus far been made, supposed to be divided into three principal mass- 



