128 
Modern Business Geography 
Near coal mines may be seen 
great piles of refuse material 
called culm. This refuse con- 
tains slate and bits of coal. 
The thrifty Europeans mix 
culm with coal tar and make 
small bricks, “ briquettes,” to 
burn. Cities having large 
manufacturing populations, if 
situated near enough to the 
culm piles to secure cheap 
transportation, would prob- 
ably be glad to buy these 
briquettes. Name some such 
cities. Would your commun- 
ity furnish a good market for 
this cheap substitute for coal ? 
In their eagerness for profits 
many companies abandon a 
worked mine and seek a new 
one as soon as the most acces- 
sible coal seams are exhausted. 
After an abandoned mine has 
caved in, it usually does not 
pay to reopen it for the small 
amount of coal left there. 
How does more effective min- 
ing machinery help to remedy 
this waste? 
Coke, the fuel necessary for 
iron smelting, is made by 
baking coal in great ovens. 
Two kinds of ovens are used, the * beehive” and the “retort.” In the 
beehive oven, coke is the only product. In the retort oven the valuable 
gases are saved, and the following products are obtained in addition to 
the coke: coal tar, ammonia, benzol, illuminating gas, graphite, oils, 
dyestuffs, disinfectants, explosives, and substances used in medicine. 
Find out how many of these by-products are used in your home. 
How the civilized world depends upon petroleum. 
Is petroleum used in the crude state? Consult an encyclopedia or a 
book on petroleum. 
Suppose that there were no more petroleum in the world. Consider in 
how many ways your life would be affected by lack of the following 
products made from petroleum: gasoline, naphtha. benzine. kerosene, 
lubricants, oils, vaselin, parrafin. 
In 1929 the United States consumed almost a billion barrels of petroleum. 
Some persons think that this is at least one twentieth of our untouched 
2 
Fig. 101. A “gusher” in the Sunset oil field of Cali- 
fornia. The drillers struck a deposit of oil and gas 
under great pressure, and a column of oil and gas 
shot up 150 feet. For several weeks the well lowed 
at the rate of 40.000 barrels of oil a day. 
E. 
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