CHAMPLAIN DIVISION. 
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belongs to the Rowley family. This last has been extensively worked, but for many years 
slate has been so cheap as to render the working of these quarries unprofitable. The slate is 
of good quality, (but softer than the Welch slate,) and there is an inexhaustible quantity of it. 
At Hillsdale, a quarry of slate was wrought extensively some years ago, by Mr. Foster. 
The slate is of good quality where it is free from pyrites, but a large portion of it contains 
disseminated cubic crystals of this mineral. By exposure to the weather, the crystals de¬ 
compose, and leave cubic cavities in the slate. The pyrites is an injury to the slate, not only 
by leaving cavities through which leakage might take place after it should be placed on roofs, 
but by its decomposition it changes the texture of the slate.* 
Many localities were also observed in different parts of this range, at which quarries have 
never been opened, but which would undoubtedly afford roofing slate of a superior quality. 
Others no doubt might be discovered, should the price of the article justify a further explo¬ 
ration. Indeed the quantity of slate, suitable for roofing, contained in this range of mountains 
and hills, can be estimated only by saying that it is sufficient to supply a nation’s wants for 
ages. From its observed range and extent, it is believed that careful examination would lead 
to the discovery of favorable locations for working it for roof slate, in Dutchess and Ulster 
counties near the Hudson, where the range of rock crosses the river, and in Vermont at no 
great distance from Lake Champlain. 
Roof-slate is frequently carbonaceous, and passes into graphic slate. A locality of this 
slate is in the road near Mr. Asa Felton’s, and near the line between Austerlitz and Hillsdale. 
It had been described to us as a locality of black oxide of manganese. This variety of slate 
also occurs on the mountain one and a half miles south of Hillsdale ; in Ancram, one-half 
mile to one mile west of the lead mine, and in many other places ; but it is not so black in 
these two last localities as in other places. It breaks out in columnar fragments. Much of 
this columnar slate is similar to pencil slate, and might probably be applied to this use. 
Many of the slate rocks of Columbia and Dutchess counties are so loaded with carbon, 
either disseminated or in thin fdms of anthracite, which fills the natural fissures, cleavages, 
and breaks of the rock, that many persons have expended time, labor and money in digging 
for coal. , ■ ' 
* About half a mile southeast of Bain’s tavern, is an old slate quarry. A quarter of a mile north of Pulver’s corners in North¬ 
east, roof-slate from the same range, containing cubic cavities, is used as a fire-stone. This kind of rock, laid edgewise, is 
generally used for the lining of furnaces in that part of the country. 
