90 
GEOLOGICAL REPORT—THIRTY-FIFTH PARALLEL. 
to Puget’s sound. It burned with much flame—so much that the flames often poured out of the 
top of the chimney for ten or twenty feet. This shows how highly the coal is charged with 
bitumen and volatile ingredients, and indicates its value for making gas. It was thought that 
the coal produced a large quantity of slag and cinder, and the fires required raking every 
twenty minutes. This is a general complaint from those who use the coal in furnaces with a 
strong draught, and it is doubtless true that the amount of ash is large, and that it is readily 
fused together. A peculiar form of furnace may obviate the difficulties which arise from this 
peculiarity of the coal. This is important, as in other respects the coal is apparently equal to 
any. I have already given all the facts which could be obtained regarding the geological 
association and occurrence of this coal in my Preliminary Geological Report. 1 It is in all 
probability of Tertiary age, and I am inclined to regard the strata as belonging to the same 
series as the sandstone and shales of San Francisco. 
Vancouver s Island coal.- —The coal of Vancouver’s island is probably similar to that from 
Bellingham bay, and was also tested on board of the steamer Active. The locality is about 
eight or twelve hours’ run by steamer from Bellingham bay, at the port called Nanaimo. I saw 
this coal in use on the steamer, and found that it produced a large quantity of very fluid slag, 
which ran down in streams from the grate-bars. 
Cowlitz coal. —Another large deposite of coal has been known for several years in California, 
and is now being explored by a company of gentlemen in San Francisco. It is found near the 
coast, on the navigable waters of the Cowlitz river, and is reported to be equal to the Bellingham 
bay coal. It is much nearer San Francisco and San Pedro, and has that advantage over the 
Puget sound mines. A specimen of this coal was brought home by the Exploring Expedition, 
and Avas analyzed at the Yale College laboratory by Professor Benjamin Silliman, jr., with the 
following result: 
Carbon_ 45.56 
V olatile ingredients. 52.08 
Ashes. 2.36 
It burned with much smoke. 2 
Bitumen, or asphalt, of Los Angeles. —The bitumen of the vicinity of Los Angeles will 
doubtless at some future day become extensively used for the manufacture of gas, and for various 
purposes in the arts. In the moderate climate of the Pacific coast it cannot but become an im¬ 
portant article for the construction of pavements, cisterns, &c. It is already used for forming 
roofs, being spread out in quantities on nearly flat surfaces, and softening by the heat of the sun 
so as to make a water-tight covering. 
BUILDING-STONE. 
Granite, or gneiss, suitable for ordinary railroad constructions, can be obtained in the Ber¬ 
nardino Sierra, along the Mojave and the Colorado, along the valley of the HaAvilhamook, or 
Bill Williams’ fork, and in Cactus Pass. Granite also forms, according to the descriptions, 
a comparatively isolated outcrop at the southern base of the San Francisco volcano. From the 
last-mentioned point, eastward to the Sierra Madre, it cannot be obtained except by transporta¬ 
tion. It can be procured in the Sierra Madre, and again at the Sandia and Santa Fe mount¬ 
ains. East of the Sandia mountains it cannot be had along the line, if we except the Witchita 
mountains, Avhich rise several miles south, but which could be resorted to for stone if required. 
Limestone and sandstone. —Portions of the route betAveen the granitic outcrops are supplied 
with building materials in the sedimentary rocks of carboniferous or later age. Thus, betAveen 
Cactus Pass and the granite at San Francisco volcano, there are numerous exposures of lirne- 
1 Preliminary Geological Report, accompanying the report of Lieutenant R. S. Williamson, U. S. Topographical Engi¬ 
neers. H. Doc."129, p. 72. 
2 Report on the Geology of the Exploring Expedition, by James D. Dana, p. 658. 
