20 Miscellaneous Localities of Minerals. 
a 
discovery or application of American clays, but we have 
succeeded in procuring a supply of the celebrated Stour- 
bridge clay, and Sunderland firestone, from England, and 
have given them a short but satisfactory trial. Besides 
these we have used the Haverstraw and Smiibfield firestone, 
and approve of them both. The use of stone, instead of brick, 
in the construction of furnaces, is attended with great saving 
of expense, not only in the first outlay, but in subsequent re- 
pairs ; and when the stone is past use for its primary object, 
it affords a good substitute for burnt clay, in the composi- 
tion of firebrick and melting pots. The stone and sand of 
our own country, so far as our experience extends, are equal 
in quality to ihe imported, and lower in price. 
The specimens alluded to are numbered and described as 
follows ; and a note is now added as to their nature —Ed. 
No. 6. Firestone from Sunderland, England, an article 
extensively used in that country, for furnaces and forges; 
it blocks freely, and is wrought with ease. It is the first im- 
portation here. This is a white silicious,sandstone. 
No. 7. Firestone from Haverstraw, New-York. It splits 
and works as free as the Sunderland, and its cost is little 
more than half that, taking freight and duties into ac- 
count. ‘This is the old red sandstone which underlies 
the greenstone trap of New-Jersey, Connecticut and Massa- 
chusetts, and probably would be found of a good quality in 
all these regions. 
No 8. Firestone from Smithfield, Rhode-Island, which 
stands a high temperature, perhaps better than either of the 
others, but is generally obtained in rugged masses, is wrought 
with great difficulty, and requires expensive transportation ; 
it will cost when wrought probably double the price of Eng- 
lish. This is a very fine granular quartz, arranged in layers, 
with intervening mica, also in iayers. It is probably derived 
from a gneiss or mica slate formation. The fine-grained mica 
slates are frequently among the best fire-stones. The late 
Mr. Whitney, of New-Haven, used with much advantage the 
remarkable stone of this description from Boiton and East- 
Hartford. This stone is also much used for grindstones, 
and for flagging-stones, as it splits easily in large and beauti- 
ful slabs. 
No. 9. Clay from Stourbridge, England, celebrated for its 
resistance to heat. Like the Sunderland stone, it is an article 
of prime importance, and extensive use, in English glass ma- 
