Coal. 45 



the Map, the two localities will be seen to be separated by granite 

 and gneiss, from twenty to thirty miles across. The Worcester coal 

 occurs in an imperfect kind of mica slate. It is what Humboldt calls 

 trasition mica slate : for a few miles north, it passes into distinct argil- 

 laceous slate. Following the range south from Worcester, it be- 

 comes more decidedly micaceous, and probably there forms a bed in 

 gneiss. Indeed, in Dudley, I saw the same rock surrounded by 

 gneiss, and highly impregnated with anthracite. 



The bed of anthracite in Worcester, is about seven feet thick, and 

 has a moderate dip to the northeast. It has been explored only a 

 few feet, and the operations are now suspended. To continue them 

 advantageously, it will be necessary to go down the hill, and remove 

 the soil so as to find the lateral outcrop of the bed, in order to avoid 

 an accumulation of water. This work has been already commenced. 



The Rhode Island beds of this coal were opened several years 

 ago, before the value of it was justly appreciated by the community. 

 The sales not being brisk, the works were abandoned, and have never 

 since been resumed ; so that on account of the rubbish, I was unable 

 to ascertain the width of the beds. I have always understood, how- 

 ever, that there was abundance of coal. The beds are less favorably 

 situated for working, than that at Worcester. 



The extensive, and rapidly increasing demand for the Penn- 

 sylvania coal, is a conclusive testimony to its first rate excellence. 

 The experiments of Mr. Bull of Philadelphia, as well as those 

 of Professor Silliman, recorded in the eleventh volume of the 

 American Journal of Science, show that the best Rhode Island 

 coal is not greatly inferior. The Worcester coal, burns with more 

 ditjjgulty; but gentleman who have fairly tried it, and on whose 

 testimony I can depend, assure me, that it may be employed suc- 

 cessfully, and comfortably for fuel. There can be no doubt, that 

 its quality is inferior to the coal of Pennsylvania, and also to that of 

 Rhode Island,* But it may be very much inferior, and yet for many 

 purposes, be exceedingly valuable. The fact is, anthracite has to 

 struggle with prejudices wherever it is first introduced, arising chiefly 



* According- to the experiments of Mr. Bull, a pound of the best Pennsylvania 

 anthracite maintained ten degrees of heat in a room, 13 hours and 40 minutes ; a 

 pound of the Rhode Island coal maintained the same heat in the same room, 9 hours 

 and 30 minutes ; and a pound of the Worcester coal, kept up the same heat only 7 

 hours and 50 minutes. It is a curious fact that the specific gravity of the Worces- 

 ter coal, is one third greater than that of the coal from the two former localities. 



