Geology of Massachusetts. 55 
The red oxide of tron is found, in comparatively small quantities, 
at the localities above mentioned. It exists, also, in other places 
in the State; although it is not, as yet, found in large quantities. 
Argillaceous oxide of iron is likewise found at most of the hema- 
tite beds above described. 
In Cranston, R. 1. 
From this place General Leach procures, as he told me, very ex- 
cellent brown oxide of iron, for the supply of some of his furnaces 
in Massachusetts; and he represents the bed as inexhaustible. 
Argillaceous Oxide of Iron. 
This is the most common species of iron ore in Massachusetts. 
There are several varieties found here. On Nantucket and Mar- 
tha’s Vineyard, particularly at Gay Head, we find the slaty and 
nodular varieties; and at the latter place, according to F’. A. Green, 
Esq., is found the columnar variety. On the Vineyard these varie- 
ties are abundant enough to be an object for the manufacturer; and 
during the last war, I was told, they were employed in the furnaces 
on the continent. Ina pond, in Sharon, has been found the lenticu- 
lar variety of this ore. 
Bog Ore. m 
This variety of the argillaceous oxide, is far more abundant than 
any other, and has been used extensively in the manufacture of cast 
iron; for which it is chiefly adapted. In the following towns it is 
found in large quantities: viz. Groton, North, West, and South 
Brookfield, Carver, Hopkinton, Hardwick, New Braintree, Oak- 
ham, Berlin, Sturbridge, Southbridge, Freetown, Dartmouth, Ro- 
chester, Troy, Easton and Sharon; and in the following, it exists in 
greater or less quantities; in Middleborough, Malden, Seekonk, 
Sheffield, Templeton, Warwick, Williamstown, Greenfield, North- 
ampton, Springfield, Williamsburgh, Dalton, Holland, Wales, Nor- 
ton, Mansfield, Bridgewater, Stoughton, Spencer, Gloucester, and 
on Martha’s Vineyard ; indeed I can hardly doubt that more or less 
of this ore may be found in nearly every town in the State. It was 
so common that, at length, I ceased to inquire for it, and the locali- 
ties are so numerous that I have not attempted to exhibit them all 
upon the Map. 
it ought to be recollected, that the process by which bog ore is de- 
posited, is in many places tow going on, particularly at the bottom 
