BUILDING AND ORNAMENTAL STONES. 459 



stone, soft and easy to work, and apparently fairly durable. It has 

 been used in some of the finest stone fronts in Columbus, in this 

 State. 



According to Professor Orton,* however, the stone is brown only on 

 the outcrop, and a few feet from the surface assumes a dark blue- gray 

 color, and loses its value as an ornamental stone, since it contains a 

 large amount of soluble iron protoxide, which produces bad discolora- 

 tion on exposure. An analysis of this stone is given in the tables. 



Oregon. — Two miles south of Oakland, Douglas County, in this State, 

 there occurs an extensive deposit of a fine, dark blue-gray sandstone, 

 which changes to a drab color on exposure. It occurs in layers of 17 

 to 36 inches in thickness, parted by shaly seams, and is readily quarried 

 by means of wedges. Quarries were opened in 1879, but have not been 

 extensively worked as yet. A fine-grained sandstone, said to be suita- 

 ble for either building or ornamental work, also occurs about 14 miles 

 from Portland, in Clackamas County. It has been quarried since 186G, 

 and used in some prominent structures in Portland. 



Pennsylvania.— The belt of Triassic sandstones passing through south- 

 western Pennsylvania is described as beginning at the west bank of the 

 Hudson Kiver and extending in a broad belt from the Bay of New York 

 to the base of the first ledges of the Highlands, being bounded on the 

 northwest by this chain and its continuation. To the southwestward 

 it traverses New Jersey, Pennsylvania, Maryland, and, in a somewhat 

 interrupted manner, Virginia and part of North Carolina, its total 

 length being not less than 500 miles, and of a width varying from 10 to 

 50 miles. The principal quarry in this formation in Pennsylvania is 

 situated on the south side of a hill in Hummelstown, Dauphin County, 

 the stone dipping to the north at an angle of about 40° and the ledge 

 being about 85 feet in thickness. The rock is evenly bedded, the courses 

 varying from 3 to 10 feet in thickness, the joints regular and from 4 to 

 40 feet apart, so that blocks of any practicable size can, it is said, be 

 obtained. The texture is about medium fineness, and the color a deep 

 bluish brown, slightly purple. The topmost layers are, however, of a 

 reddish brown color, closely resembling the Portland stone. The stone 

 compares very favorably with any of the Triassic stones, its chief de- 

 fect, so far as the author has observed, being occasional clay holes, 

 which sometimes have an unpleasant way of making their presence 

 known in unexpected and undesirable places. The Hummelstown stone 

 is now in very general use in all our principal Eastern cities. 



Stone from the same formation and differing, if at all, only in slight 

 color and texture peculiarities is quarried more or less in other towns 

 along the belt, particularly Goldsborough, Beading, Bridgeport, and 

 several towns in Bucks County. 



The Carboniferous sandstones of Pennsylvania are little quarried 

 excepting for local use, although occasionally of good quality. Near 



*Op. cit, p. 599. 



