The Providence news. (Providence [R.I.]) 1891-1906, 1899-02-20
AIR AND COAL.
Prospect That the Worlds Suppl Of Air VIII Run
Shor Before The SuppIy Of Coal

Terrc Haute. Feb. ls.-President Leo
Mees of the Rose Polytechnic Institute
says that lack of coal for fuel in the
remote future is not the thing TO &c
feared. but scarcity of air. The sup
ply of coal may last for several GEN.
turies, but the supply of air may be-
exhausted by burning up the coal. The
coal is changed by burning from car
bon TO carbon dioxide, and the oxygen
can be liberated from the dioxide only
by plant life.
Lord Kelvin is perhaps the shrewd-
est gucsser IN speculative science that
the world has ever known" says Pres
ident Mees. on the subject OF the
total quantity of combustibies in the
world he has certainly presented some
very pretty speculations. Such an enor-
nous amount of fuel is used to relase
stored-up energy that government com
missions have been appointed to ascer-
tain as nearly as practicable the total
existing amount of available fuel in the
world. In the middle OF the century a
British commission gave the opinion
that Great Britain would be ntirely
without coal I'm a little more than 100
years. A later commission, appointed
I'm 1860. came To the conclusion that the
supply of coal above the depth of 1900
feet would last 2l2 years. No account
was taken of the coal below 1000 feet,
as IL was estimated that an amount OF
energy would be expended In raising
the coal To the surface equal TO the
amount OF energy stored up i'm the coal.
The commission of 1888 returned TO the
original estimate of 11U years as the
A.. a. L.. In. I.stf
ain. The American field was then in
spected and the conclusion of the COM
mission was that America had coal
enough to supply both its own demands
and those Of England for 600 years TO
come.
I'm bringing his attention to bear on
the subject, Lord Kelvin, In way
quite his own, began at the very oppo-
site side as a basis of reasoning. His
object was to find the total amount of
combustibles i'm the world. All oxygen
is liberated through the agency OF life.
Before the earth had life there was no
free oxygen This Is proved TO be the
fact that there Is no oxygen in meteor
lies. The amount of oxygen in the at
mosphere can be determined from the
proportion il bears to the total amount
of air. In round numbers. it requires
three tons of oxygen TO burn one ton
of combustibles. This oxygen has al
ways been liberated by the action of
vegetation from carbon compounds eN-
listing. The question arises as TO the
rate at which oxygen is being thrown
into the air. Assume that the present
surface is covered with vegetation.
There are y, 100000 square miles on
which vegetation can grow. Such vege-
tation can give. on the average, 800
tons of combustibles square mile eacn
year. This would be equal TO 100 tons
of the best coal. Thus II would be pos
sible to produce combustibles equiva-
lent To 1000 900, 900 tons OF coal each
year IL we burn more than 100 tons
Of coal per square mile the earth over
we shall throw more carbon dioxide in
TO the air than we can reconvert into
oxygen by plant life. Thus, the danger
is not that we may run out of coal. but
that our supply of air may be exhaust
ed. We shall be deprived of air before
we are of coal. We are now mining
fifty tons of coal square mile in this
country. We are already throwing into
the air one-half as much carbon diox-
ide as II il possible TO reclaim by plant
life.