418 REPORT ON NATIONAL MUSEUM, 188G. 



Fundy than to any other at present in the collection. If the specimen 

 received at the Museum is a fair sample of the rock at the quarry, it is 

 certainly a most excellent stone, though its otherwise uniform texture 

 is often interrupted by the presence of oval or rounded black patches 

 or knots, caused by segregations of mica, hornblende, and other iron-rich 

 minerals. This is, however, a defect not uncommon in many of the 

 Maine granites.* 



Maryland. — The most noted quarries in this State are situated in Bal- 

 timore County, near Woodstock. The rock is a biotite granite, varying 

 from light to dark gray in color, and of about medium texture. It is 

 used extensively for general building purposes and for monumental 

 work in Baltimore, Washington, and some of the Western States. At 

 Mount Koyal and opposite Ellicott City fine-grained dark-gray gneiss 

 is quite extensively quarried for general building purposes, curbstones, 

 etc. A part of this rock is beautifully porphyritic through large felds- 

 pars an inch or more in length. 



A dark-gray gneiss, which is the principal stone used in Baltimore 

 for rough work, is quarried in the immediate vicinity of the city. 



At Port Deposit, in Cecil County, a gray biotite gneiss is extensively 

 quarried, and is used chiefly for bridge building, docks, harbor improve- 

 ment, and general building work. It has been used in the construction 

 of Haverford College, Md., St. JDominick's Church, Washington, and 

 several churches in the immediate vicinity. Other locations where 

 good quality of granite is exposed, but not quarried to any extent, are 

 Gwynn's Falls, in Baltimore County, and 3 miles east of Bockville, in 

 Montgomery County. 



All of the Maryland granites and gneiss at present quarried have 

 biotite as their chief accessory, are of a gray color and of medium fine- 

 ness of grain. They appear, however, better adapted for general build- 

 ing than for ornamental work. 



Massachusetts. — As Massachusetts was the earliest settled of the New 

 England States it is but natural that here the systematic quarrying of 

 granite should first be undertaken. As already noted,t granite from 

 the bowlders on the Quincy Common, and from Chelmsford began to 

 be used in and about Boston as early as 1737, but it was not until the 

 early part of the present century that its use became at all general* 

 Indeed it may be said that it was not until the opening of the quarries 

 at Quincy in 1825 that the granite industry assumed any importance. 

 From this time the use of the stone for general building purposes in- 

 creased in a marked degree, and the history of granite quarrying in the 

 United States may properly begin with this date. 



This early opening of quarries at Quincy was due largely to the de- 

 mand for stone at Charlestown for building the Bunker Hill monument, 



* Stee On the Black Patches in Maine Granite, Proc. Nat. Mas., 1883, p. 137; also, 

 On the Collection of Maine Building Stone in the National Museum, Proc. Nat. Mus., 

 1883, p. 165. 



t Ante p. 286. 



