30 CAPTAIN TUCKEY’S NARRATIVE. 
«¢ The valley of Trinidad, the largest and deepest ravine 
in the south side of the island, commences at the sandy 
beach of Porto Praya, and runs $.8.W. and N.N.E., with 
its upper extremity bent to the E.N-E. until it is lost 
in sloping hills. It is generally covered with volcanic 
fragments. 
«The central ridge of hills follows nearly the largest 
diameter of the island from S.E. to N.W., but nearest to 
the eastern coast, with sloping sides to the west, and having 
many steep basaltic rocks, and well watered vallies or 
ravines to the east. The peak of St. Antonio rises above 
the other mountains in an oblique, conical, sharp-pointed 
form, to the height of about 4500 feet. 
«The sea rocks round Porto Praya expose five strata to 
view; Ist, or lowest, a conglomerat, passing into pumice tufa ; 
2d, pumice ; 3d, a thin layer of porous basalt ; 4th, columnar 
basalt; and 5th, or uppermost, a basalt-like substance, 
which from its concentrical and globular forms, seems 
to have been in a semifluid state. Farther imland, the 
basaltic strata sometimes contain olivin and augite, and more 
rarely amphibole. About a league up the valley, on its 
western border, are huge rocks, which cause a bending in 
its direction, and which are composed of a deep red quartz, 
with crystals of feltspar ; about two leagues up are found 
