ARCHITECTURE. 
35T 
This compound gas is the same which collects in 
the coal-mines in England, and proves so fatal to 
the miners. 
/ 
CHAPTER XXXII. 
PRACTICAL APPLICATION OF GEOLOGY TO THE USEFUL 
PURPOSES OF LIFE. 
Architecture. — Engineering — Roads — Canals — Embankments 
— Wells — Mining. — Agriculture. 
Geology derives its chief importance from its ap- 
plication to many of those arts which minister to 
the comforts and necessities of man. A knowledge 
of the formation and structure of the earth not only 
gratifies a rational curiosity, but it directly places 
within our reach the instruments by which its use- 
ful materials may be converted to highly valuable 
purposes. Here knowledge truly is power; and 
he who is thoroughly conversant with geological 
principles and facts, possesses the lever and the 
" where-to-stand" which Archimedes wanted to 
move the world. 
architecture. 
It would seem that the importance of knowing 
and testing the durability of building stones and 
marbles for public works, or even private dwell- 
ings, is too obvious to need remark ; and still there 
has hitherto been displayed great ignorance or in- 
attention to this subject in this country, so much so, 
that frequently the worst and most perishable ma- 
terials have been selected in preference to such as 
are equally beautiful, and, in addition, indestructible. 
