34 Geology of Massachusetts. 
graywacke; but this question may be more properly considered in 
the scientific part of my report. At any rate, this rock, in the towns 
above mentioned, does not split into layers sufficiently thin for roofing. 
But it is valuable for grave-stones, the covering of drains, flagging 
stones, &c ; and for these purposes it is extensively wrought in Quin- 
cy, Charlestown, &c. 
Novaculite. 
This is a variety of argillaceous slate which is known in the arts 
under the name of hone, oil stone, turkey stone, and whet stone. It 
is in beds of argillaceous slate in Charlestown, Malden, and Quincy. 
It is not however of a very good quality; and I am not aware of its 
being used for hones, or even for whet stones; although it might 
answer the purpose, if better materials could not be found elsewhere. 
Roof Slate in Worcester County. 
The range of slate exhibited on the Map in the towns of Boyls- 
ton, Lancaster, Harvard, Shirley and Pepperell, is associated with 
the peculiar mica-slate that contains the Worcester coal. It answers 
for roofing in some parts of the bed and has been quarried for this pur- 
pose in Lancaster. It has been wrought considerably in Harvard 
and Pepperell for grave stones; and is transported a considerable 
distance for this purpose. The stratum is narrower near the north 
line of the state: but I have found no time to ascertain how far it 
extends into New Hampshire. 
Connecticut River Slate. 
Although a large part of Bernardston is represented as composed 
of this slate, yet its characters are not perfectly developed, till we pass 
into Vermont. In Guilford, Brattleborough, Dummerston, and even 50 
or 60 miles northward, it produces an excellent material for roofs, wri- 
ting slates, &c.; and extensive quarries are opened in it in those towns. 
The best slate used in Massachusetts probably comes from this range. 
In Bernardston it is quarried to some extent for grave stones. 
Berkshire Slate. 
The mica slate of the western section of the State, passes gradual- 
ly into roof slate, and in most instances the characters of the lat- 
ter are not very perfectly exhibited, until we have entered New 
York. There, however, in Hoosac, and other towns, it is quarried 
extensively for roofing: and the western part of Massachusetts is 
always sure of a supply of this valuable material from that quarter ; if 
not within its own limits. 
