36 



Economical Geology. 



red sand, cemented probably by iron. It is remarkably uniform in 

 its color and composition ; and forms a beautiful and most valuable 

 building stone ; though liable to be easily injured and sometimes dis- 

 integrating by exposure. The quantity of this rock is inexhausti- 

 ble, and it occurs only from three to five miles from Connecticut riv- 

 er ; the intervening region being nearly level. A great number of 

 quarries are now explored ; but I have no means of determining how 

 great is the demand for the stone. The celebrated Chatham quar- 

 ries, on the banks of Connecticut river, in Connecticut, are opened 

 in the same kind of rock, although of a coarser variety. 



Another variety of the new red sandstone, quarried in many places 

 in Massachusetts and Connecticut, is coarser than the Long Meadow 

 stone ; but being harder, it is more enduring, though less elegant. 

 This variety is quarried extensively for the Farmington Canal in the 

 sandstone range south of Mount Tom in West Springfield. A 

 gray and rather coarse variety is used in some places, e. g. in Gran- 

 by, (Mass.) This indeed, with the other varieties mentioned above, 

 forms excellent underpinning, door and window caps, and foundations, 

 and door steps ; and, like the Berkshire marble, they are sometimes 

 wrought into sinks and other similar articles. The ease with which 

 the rocks of this formation are wrought, forms a great recommenda- 

 tion ; and were they as enduring as gneiss and granite, these latter 

 rocks would soon be neglected. 



Tertiary Formations. 



I suspect there are only two varieties of these formations in Mas- 

 sachusetts ; one developed most perfectly in the west part of Mar- 

 tha's Vineyard, and the other, and the most extensive, along the Con- 

 necticut river, although common in limited patches all over the State. 

 Neither of these formations furnishes stones sufficiently firm for arch- 

 itectural purposes, although in a few instances, I have observed lim- 

 ited beds of the clay, sand and pebbles, that compose these forma- 

 tions, to be in a state of consolidation. Nearly all our clays, howev- 

 er, are in the tertiary formations, and these are so important in an 

 economical point of view, as to demand a particular description. 



Porcelain Clay. 



This is the purest of all the clays, and is the only one employed in 

 the manufacture of porcelain, or China ware. It results from the 



