420 EEPORT ON NATIONAL MUSEUM, 1886. 



feet thick have been loosened from the bed in a single piece, while it is 

 estimated a block 200 feet long 50 feet wide and 20 feet thick conld be 

 obtained if desired. The principal markets are ISTew York, Boston, 

 Kew Orleans, and Cuba. 



Biotite granites. — Several important quarries of coarse biotite granite 

 are worked in this State, but their product is mostly used in the near 

 vicinity. Light pink varieties admirably adapted for rock-faced work 

 occur at Brockton, Milford, and North Easton. The Milford stone, 

 though not extensively quarried, is particularly elfective when used in 

 this manner, as is well illustrated in the new city hall at Albany, N. 

 Y., and also in the new railway station at Auburndale, Mass. At 

 Framingham, Leominster, Fitchburgh, Clinton, Fall River, and Freetown 

 are also quarries of coarse gray but apparently strong and durable 

 granites of this class. 



Eiridote (jranite. — This is a rare variety of granite in this country, the 

 quarries at Dedham producing all that is now upon the market. The 

 stone is fine-grained and of a light pink color. Besides ejiidote, which 

 is visible to the naked eye as small greenish specks, it contains numer- 

 ous flecks of chlorite, resulting from tlio alteration of a black mica. 

 The stone works readily and gives very pleasing effects either in polished 

 or rock-face work. It is of this stone that was constructed the new 

 Trinity Church in Boston, and which is considered by good authorities 

 to be, from an architectural standijoint, the finest building in America. 



Gneiss.— A fine-grained very light gray, sometimes pinkish, muscovite 

 gneiss of excellent quality has been quarried more or less for the past 

 thirty-five years near the town of Westford. Other quarries of gneiss 

 are at West Audover, Lawrence, Lowell, Ayer, several towns in Worces- 

 ter County, at Becket, Northfield, and Monson, as will be noted in the 

 tables. 



Being in most cases distinctly stratified, these gneisses are not 

 adapted to so wide a range of application as the massive granites, but at 

 the same time the ease with which in many cases they can be quarried 

 makes them particularly valuable for foundations, bridge abutments, 

 curbing, paving, and rock-faced building. At the Monson quarries, for 

 instance, the rock is divided by a series of joints, approximately parallel 

 to the surface of the hill on which the quarries are situated, into im- 

 mense lenticular sheets from G inches to 10 feet in thicknes. By tak- 

 ing advantage of these natural facilities a block was split out in 1869 

 which measured 354 feet in length by 11 feet in width and 4 feet in 

 thickness. An analysis of the Monson stone from the Flynt quarry is 

 given in the tables. 



As a general rule it may be stated that while the granites and 

 gneisses of Massachusetts are good and safeworking stones they are 

 coarse and in no way remarkable for their beauty. In the matter of 

 color and texture they bear a striking contrast to the fine and evou 

 grained stones of her sister States, Connecticut and Khode Island. 



