8 Introduction. | Jan. 
makers will, of course, be greatly benefited, and will compete more 
successfully than they do at present with the Lancashire manufac- 
turers for the supply of all the western markets. 
As to the fortunate ironmasters, they will not only have found an 
unexpected mine of wealth in the salt-beds, but in the evaporation of 
the brine, they will be enabled to utilize the waste heat from their 
puddling and blast furnaces, as well as from their coke-ovens; thus 
adding profit to profit, and carrying out in an unexpected manner the 
economical principles recommended by the President of the British 
Association. 
Closely allied to the question of Coal, is that of Petroleam—a 
natural product which is likely to exercise an important influence upon 
civilization. This hydro-carbon, some forms of which have long been 
known in India, has recently been found to exude from certain wells 
or springs in Pennsylvania and Canada. It is supposed to arise from 
the destructive distillation of a mineral bitumen beneath the surface, 
and on reaching the hand of man, it is subjected a second time to the 
distilling process, when it yields three distinct substances of consider- 
able value. The first is a spirit, which is employed as a cheap substi- 
tute for turpentine; the second, a burning oil of great brilliancy, 
capable of being used in lamps of an almost nominal value, and itself 
procurable at an average price not exceeding half that of rape-oil ;* and 
lastly, a kind of grease which is employed for lubricating coarse ma- 
chinery. The importation of this substance (chiefly in its distilled 
form) is increasing rapidly, and may be reckoned by millions of gal- 
lons, and almost the only thing requisite to enable it to rank amongst 
our leading commercial staples, is an inexpensive air-tight cask, in 
which it may be stored, so as to obviate the enormous leakage which 
often causes it to be a ruinous venture to importers and dealers. 
These are but two or three of the interesting results or applications 
of that geological knowledge, the development of which must neces- 
sarily occupy a prominent place in our pages; and being of a prac- 
tical character, we have selected them for comment, in preference to 
those which bear upon the principles of the science itself, such as the 
Origin of Rocks, Earthquakes,t the Paleontological Evidences as to 
the Antiquity of the Human Race, and many other subjects which are 
now engaging the attention of scientific men. 
Before quitting terra firma to follow the researches of Science into 
space, we must direct our attention for a few moments to the work of 
* The wholesale price of the finest Petroleum Oil is now (November) one 
shilling and ninepence per gallon; of Rape or Colza Oil, three shillings and 
eightpence per gallon. 
+ On this subject, am article will be found in the present number, by Mr. Mallett. 
