The Washington herald. [volume] (Washington, D.C.) 1906-1939, 1907-07-23

Cement making is an industry which
has grown a thousand fold in twenty-five
years. which Is fifty times greater than
it was ten years ago. which increased 30
per cent last year, and which in its short
life has come TO rank with the first min
eral industries of the land. 1t now has
the claim to the first place in the honor
roll OF those mighty Commercial forces
which are operating 10 make the United
States the foremost Of the nations, Only
coal and pig ron rank ahead of cement
in the value of productions from the
EARTH and cement and iron ore are now
running neck and neck Cement long ago
passed the gold mines; lead and zinc TO
gether are not nearly so valuable, and
silver and copper are no longer contend
ers in the race. The United States began
TO make Portland cement in 1875. Five
years thereafter the annual production
had reached 1900 barrels. By 1895 the
output had reached the million-barrel
mark, and last year the Portland cement
produced in this country amounted to
IS, 400 900 barrels.
Portland cement Is the most versatile
material man has ever used in construc-
ton. 1t is taking the place OF timber
for piles. telegraph and telephone posts,
railroad ties, fence posts. and even shin
giles. Ii is used for building bridges
where steel was the only possible ma
terial ten years ago. 1t is used for dams,
locks, retaining sea walls and break
waters where stone masonry was lmper-
alive a few years since. It is used for
chimneys and sidewalks instead Of brick
II is used for grain bins instead Of any
other material. Reinforced with bars and
rods Of steel. the Portland concrete goes
into q monolithic building twelve stories
high. Pressed into hollow blocks it goes
into small cottages which initiate houses
of stone.
There are three kinds Of cement which
are Of Importance: Portland, natural, and
Puzzolan. Natural cement has been made
in the United States for nearly a hundred
years, having been employed in construct
ing the Erie Canal, in 1873 The industry
nOuTished, showing a gradual growth
from year to year, until two years ago.
when it began to show an actual de-
crease and il is now on the wane. En-
gineers do not condemn ii, and they re-
gret that the industry is dying out.
Natural cement is made by burning
naturally impure limestone of a clayey
nature at a comparatively low tempera-
ture, about such as IS used in burning
lime The burned stone IS ground to a
powder and is then ready for use.
PuZZolan cement is the oldest of ce-
ments, and was made by the ancient
Romans It is prepared by mixing pow
dered slaked lime with volcanic ashes. In
the United States the Stag from iron
furnaces is substituted for the volcanic
ashes, there being little or no chemical
difference. This cement is better for use
under water than in air
Portland cement IS Of comparatively re-
cent origin. II was first made in Leeds,
England. by Joseph Aspdin. in 1924 On
account Of its similarity, in appearance,
TO a certain building-stone known in
England as Portland Stone" it was at
once called Portland cement It is made
by burning a Underground artificial mix
ture of lime with silica. alumina. and iron
oxide. IN definite proportions. at tenn
perature approximaung 5000 degrees. The
mass is thus reduced TO a 'ClnkeT,"
which is then ground into a very fine
powder ready to use. It will harden
under water, but Will not successfully
resist the action of salt water Quite
recently il has been found that by re-
ducing the amount of alumina and in
creaslng the iron. the Gem mt may be
used in salt water. the alumina being
the vulnerable portion Of the compound
when attacked by sea water.
The figures given in this article relate
10 Portland cement only. The manufac-
turers who sold 100000 worth in 1905
sold S50000O0O worth the next year and
the increase for 1907 is expected TO be in
the same proportion. From 1870 to 1880
the price of Portland cement was the
price Of the German product, plus the
freight, going from 81 TO s. d barrel in that
time. With the growing importance Of
the American industry, the prices dropped
sharply after 1890. reaching the lowest
average, about So cents a barrel, in 1904
The demand in the last two or three years
has been so great however. that the price
has again risen, and for the last year the
average was about SI-15.
The manufacture of cement has proved
to be a very profitable business, but only
when undertaken on a large scale. Ac-
cording to experts, the smallest plant
which could be expected to pay a re-
mUneTative return would be a fOur-kiln
mill, which would cost S5O0,OC0 to erect.
A ten-kiln plant would cost $1.00ot00 to
8, 100000. Half Of the Portland cement
Of the country is made in Pennsylvania.
the largest plant being at Northampton
In the Lehigh Valley. The Missouri and
Kansas plants come next. while in Cali
fornia there is a wonderful growth Of the
Industry, due in part to the enormous
amount of cement being consumed in the
reconstruction of San Francisco.
The chief fault to be found with con-
crete for construction purposes is that a
mistaken idea has been spread broadcast
in the minds Of people that anybody can
work with it. even to erecting buildings.
Therefore, when no engineer is employed
the advice of a concrete expert is not
asked. and common labor is put TO work.
a building sometimes COllapses before il is !
finished, just as a brick or stone or steel
building would collapse under similar |
circumstances. Where the concrete build |
ing IS properly constructed it is almost |
perfectly safe, as was proved in the Bal |
timore fire and in the earthquake and /
fire at san Francisco. the most severe |
tests 10 which any building could be sub |
jected.
For smaller houses and residences. the /
use Of concrete building blocks is spread !
ing rapidly. AS the blocks can be made !
creasins use Of this material is adding /
TO the artistic merit Of small cottage con
stTuCtiOn Thomas A. Edison has a /