S. F. Peckham—Pitch Lake of Trinidad. 47 
Yet it must not be assumed that the cosmical agencies that 
produced this deposit of bitumen have ceased to be active, or 
are even simply quiescent. Abundant evidence is to be found 
in the neighborhood and even within the lake itself, that such 
forces are still active. A few miles to the southwest of the 
lake, at Guapo, large springs of maltha or “liquid asphaltum ” 
are now flowing, and within the boundaries of the lake near 
the power station of the tramway, and within only a few rods 
of the edge of the cone, I observed what the workmen called 
(and very properly) a “blowhole.” This was a circular hole, 
about six inches in diameter, from which bitumen, more nearly 
fluid than any I saw elsewhere upon the island, had been 
ejected to the amount of perhaps a barrel. It was so soft as 
to flow readily, of a brilliant black color, and appeared to con- 
tain little, if any, mineral matter. I was told by a workman 
that such holes occurred quite frequently and so far apart as 
apparently to have no connection with each other. 
Asphalt beds occur in California that are the product of the 
hardening of maltha, or mineral tar, which escapes over a con- 
siderable area. Sometimes it flows continuously from a central 
orifice, but oftener the flow through the hot summer seems to 
be arrested by the lower, winter temperature, when the orifice 
through which the flow took place becomes plugged. ‘The 
succeeding season the maltha issues along a line of less resist- 
ance and fiows through the summer, when it in turn becomes 
plugged. These plugged orifices are often several rods apart 
for successive seasons, and present the appearance of a cica- 
trix. I have no doubt that more extended observations than I 
was able to give would reveal a similar condition of outflow at 
and in the vicinity of the lake. 
I carefully studied these phenomena as likely to offer some 
suggestion concerning the origin of the deposit. As a descrip- 
tion of the observed facts, I can add nothing to that.of Mr. 
Manross. I do not understand why Messrs. Wall and Sawkins 
observed nothing of the sort described by him, or thought it 
not “very obvious to what force or what influence this is 
attributable.” These “areola” are very irregular in shape. 
I think their form may be, to some extent, determined by the 
weight of water pressing against their sides. The surface of 
each one is slightly rounded from the center to the edge of the 
water; they then round off at a very sharp angle, finally 
descending almost perpendicularly. These areas consist of 
pitch inflated with gas to such an extent, that when broken 
into, the structure exactly resembles an over fermented cheese 
—hence the term ‘“cheese-pitch.” The cavities are from one 
to three or more inches in dimensions. The gas that they con- 
tain is constantly rising to the surface, where it bubbles out 
