233 
Guppy Reprint 
8 
Page 112 
There can be no doubt of the existence in the Caroni car- 
bonaceous series (Miocene^ and its equivalents both to the 
north and to the south of the central ranges of extensive 
deposits of tertiary coal which will sooner or later be of much 
vmlue to the island. The seam which is the subject of this 
paper is not at present worked to a greater depth than eight 
or ten feet, owing to the influx of water, which cannot 
easily be drained off, but would require engine power if the 
pits are carried much deeper. Moreover, the clays cave 
in, and would require appliances such as are generally used 
in mining operations to keep the pits open. But as the seam 
runs into the hill a greater depth of it will at ever)' step be 
available without serious hindrance from water, provided 
proper means be u.sed to prop the working and prevent 
caving in. 
Want of time and opportunity prevents me at present from 
following up this subject more closely, but I trust hereafter 
to be able to pay some attention to it. 
I have seen specimens of coal from other seams in the 
Montserrat district, which, owing to their less friable nature, 
will probably prove to be of higher value. The Williamsville 
coal may prove useful for making gas, and also for smithy 
purposes ; but to be adapted for general purposes without 
waste it would have to be manufactured into a form similar 
to the so-called “patent fuel.” In any case, however, the 
precise value of the article must be determined by experi- 
ment, for it is difficult to pronounce upon its exact qualities 
by inspection only. A reference to the geological map will 
show that the existence in the neighborhood of the Guara- 
cara of deposits of asphalt and petroleum has already been 
indicated ; and some recent discoveries of glance asphaltum 
