THE OLD RED SANDSTONE. 141 
through some of the larger flags, without shattering the edges 
of the perforation. Hence its value for various purposes 
which common sandstone is too brittle and incoherent to 
serve. It is extensively used in the neighborhood as a roofing 
slate; it is employed, too, in the making of water cisterns, 
grooved and jointed as if wrought out of wood, and for the 
tops of lobby and billiard tables. I have even seen snuff- 
boxes fashioned out of it, as a sort of mechanical feat by the 
workmen, —a purpose, however, which it seems to serve only 
indifferently well,— and single slabs of it cut into tolerably 
neat window frames for cottages. It is most extensively used, 
however, merely as a paving-stone for lobbies and lower 
‘floors, and the footways of streets. When first deposited, and 
when the creatures whose organic remains it still preserves 
careered over its numerous platforms, it seems to have existed 
as a fine, muddy sand, formed apparently of disintegrated 
grauwacke rocks, analogous in their mineral character to the 
similarly colored grauwacke of the Lammermuirs, or of pri- 
mary slates ground down by attrition into mud, and mixed up 
with the pulverized fragments of schistose gneiss and mica 
schist. 
I was first struck, on descending among the workmen, by 
the comparative abundance of the vegetable remains. In 
some parts of the quarries almost every layer of the strata is 
covered by carbonaceous markings—jirregularly grooved 
stems, branching out into boughs at acute angles, and that at 
the first glance seem the miniature semblances of the trunks 
of gnarled oaks and elms, blackened ina morass, and still 
retaining the rough bark, chapped into furrows : oblong, leaf- 
like impressions, too, and impressions of more slender form, 
that resemble the narrow, parallel edged leaves of the sea- 
grass weed. I observed, in particular, one large bunch of 
