194 Peckham and Linton — Trinidad Pitch . 



in a short time loses nearly all of the water, which is in part 

 readily re-absorbed if again exposed to dampness. 



The evaporation of the water precipitates within the pitch a 

 small percentage of saline matter, chiefly sulphates of the 

 alkalies and alkaline earths, that the natural water holds in 

 solution . The hygroscopic property of the pitch is no doubt 

 largely due to the presence of these salts. 



In selecting specimens that would fairly represent the char- 

 acter of the mass of pitch both within and without the lake, 

 we were largely governed by the appearance of the pitch and 

 the relation of the several localities to one another and the cen- 

 ter of the lake. 



No. 1 was picked up at random from the pitch taken from 

 an excavation from which the cargo of the bark "Ella" was 

 dug, during February and March, 1895. The excavation was 

 upon a village lot about three-quarters of a mile from the lake 

 towards Point La Brea. 



No. 2 is from a village lot which we have named the " Pho- 

 tograph Lot." It was here that a pit was dug and photographs 

 taken of the pit at intervals of ten days to determine whether 

 any movement in the pitch was in progress by which a cavity 

 dug in the pitch would refill. No. 2 was taken from the pitch 

 removed from the pit. This lot had been excavated about six 

 months previous and had nearly refilled, and was then being 

 uncovered preparatory to the removal of a fresh supply of 

 several thousand tons. It was about twenty rods nearer Point 

 La Brea than No. 1. 



No. 3 is so-called "Iron pitch" from the Photograph lot. 

 This is pitch that has been melted and deprived of its water 

 and gas. It is solid, of a bluish-black color, with a dull earthy 

 fracture and is slightly sonorous when struck. 



No. 4 was taken from a lot on the right hand side of the 

 road approaching the lake, that was being excavated by Mr. 

 Ghent. It came from a point 10 or 15 feet below the surface 

 on the western border of the mass filling the ravine down 

 which the overflow of pitch from the lake has taken place, and 

 nearly on the opposite side of the road from the point from 

 which No. 10 was taken. 



No. 5 is No. 4, boiled to form Epuree, in Mr. Ghent's boil- 

 ing works near Point La Brea. 



Nos. 6 and 7 were from opposite corners of a mass about 12 

 inches square and four inches in thickness. This mass was 

 taken from a point on the northeast side of the lake on the 

 outside of and near to the tramway, and was selected of con- 

 venient size from among a quantity that had been broken with 

 a pick preparatory to removal in the tram cars or carts by the 

 Trinidad Asphalt Co. 



