50 S. F. Peckham— Pitch Lake of Trinidad. — 
The concessionaires of the lake, have recently put in opera- 
tion a tramway and pier by which the pitch can be very rapidly 
and easily removed from the lake to vessels lying at the pier. 
The tramway forms a loop, which in a general way may be 
said to pass just outside the circle of islets. (See map.) In 
building the tramway much of the vegetation on these islets 
has been destroyed. The laying of the tramway presented 
some peculiar engineering difficulties, that have been success- 
fully overcome. The islands float on the pitch, and I believe 
that they represent portions of the edge of the crater broken 
off during violent irruptions and placed in, and maintained 
in their relative positions through their relations to the 
various centers of ebullition into which the surface of the 
lake is divided. These islets, which largely consist of vegeta- 
ble matter, float, while logs of wood and palm-tree ties sink in 
the pitch ; it therefore occurred to Mr. Freeman, the engineer 
in charge of the work, to support his tramway on palm leaves, 
of which many specimens are twenty-five feet in length. This 
expedient has proved a complete success, not only upon the 
summits of the “aroela” but in crossing the crevices that 
separate them. The tramway furnishes a succession of admira- 
ble points from which to view the lake, as no difficulty is expe- 
rienced in walking upon the ties around the entire loop. The 
cars are run in groups of four, which when loaded have a gross 
weight of about six thousand pounds. I carefully watched the 
passage of successive groups of these cars and could not 
observe any change of level in the road bed, as they passed 
along; yet I am quite certain if a group had been allowed to 
stand for several hours, that both tramway and cars would have 
sunk in the pitch. 
The pitch is excavated along this tramway upon the sum- 
mits of the ‘“‘areola.” Wherever the surface of the pitch is 
broken, the vesicles are uniformly smaller as the pitch is taken 
from points removed from the center of the lake. As the 
water dries out, the vesicles collapse and the color changes from 
brown to bluish black. If left long enough in the sun, any of 
the pitch, no matter from what spot it may be taken, will first 
melt upon the surface and finally flow into a more or less com- 
pact mass. The pitch being dug by the Trinidad Asphalt 
Company, both within and without the lake, was brown when 
freshly dug, changing to black on exposure. The same might 
be said of that dug farther down the slope from village lots by 
the Trinidad Bituminous Asphalt Company. It was quite evi- 
dent that as the pitch was taken from points farther and farther 
trom the center of the lake it had been subjected to more and 
more pressure, the gas being forced out as a consequence, the 
vesicles made smaller and the specific gravity thereby increased. 
