BUILDING AND ORNAMENTAL STONES. 379 



or shellac. It should therefore never be worked with hammer aud chisel, 

 but only with saw and grinding material, and no attempt made at other 

 than plain surfaces. The stone was used for the pillars in the old 

 Hall of Representatives in the Capitol at Washington, and a polished 

 slab, 31 inches long by 20 inches wide, may be seen in the National 

 Museum. The pebbles forming the stone are of so varied shades that to 

 state its exact color is a matter of difficulty. Red, white, and slate-gray 

 are perhaps the prevailing tints. On account of its locality this stone 

 has been popularly called " Potomac " marble, or sometimes " calico"' 

 marble, in reference to its structure and spotted appearance. The for- 

 mation from whence it is derived is said to commence near the month 

 of the Monocacy River and to extend along the Potomac to Point of 

 Rocks, and along the valley on the eastern side of the Catoctin Mount- 

 ain to within 2 miles of Frederick. The Curator is informed, moreover, 

 that the same formation occurs in Virginia, near Leesburgh, and that 

 here the quartzose pebbles are almost entirely lacking, thereby render- 

 ing the stone much less difficult to work. 



Massachusetts. — Crystalline limestones and dolomites of such a char- 

 acter as to assume the name of marble are now or have been in times 

 past quarried in various towns of Berkshire County, iu this State. The 

 stones are all white or some shade of gray color, medium fine-grained in 

 texture, and are better adapted for general building than for any form 

 of ornamental work. 



The quarries at Lee were opened in 1852, and the stone has been used 

 in the Capitol extension at Washington and the new city buildings in 

 Philadelphia; but little of it has been used for monuments. Iu the 

 quarries the stone lies very massive, and it is stated cubes 20 feet in 

 diameter could be obtained if necessary. The Sheffield quarries were 

 opened about 1838. The rock here is massive, with but little jointing. 

 Natural blocks 40 feet square and 3 feet in thickness can be obtained. 

 The Alford stone is used mostly for monumental work and appears very 

 durable. Much of the marble from these localities contains small crys- 

 tals of white tremolite which weather out on exposure, leaving the rock 

 with a rough pitted surface. This is very noticeable in the exterior 

 walls of the Capitol building at Washington, already noted. 



Missouri. — We have seen but few true marbles from this State, though 

 colored marbles of fine quality equaling the variegated varieties of 

 Tennessee are reported by Professor Broadhead as occurring in Iron, 

 Madison, and Cape Girardeau Counties. The Iron County stone is re- 

 ported as light drab in color, with buff veins. The outcrop occupies an 

 exposure of several hundred feet of a low bluff' on Marble Creek near 

 the east line adjoining Madison County. The Madison County marble 

 occurs near Fredericktown, and is described as the best-appearing 

 marble in the State both in regard to color and texture, the colors being- 

 red, peach-blossom, aud greenish, beautifully blended. The stone is 

 represented as very durable, but liable to tarnish on a polished surface 



