The Black Hills union and western stock review. [volume] (Rapid City, S.D.) 1904-19??, 1905-12-01

marl OF q cnalk, With q clayey material, such
as a brick clay, or a shale, and clinkering
the same at a high temperature, and grind
ing the resultant clinker into practically an
impalpable powder.
Natural hydraulic cements, such as Poz-
z%uolana, made from certain volcanic ashes
around Mount Vesuv1us, were simply
ground fine and required no clinkering, and
we're used by the Romans as early as 1000
and more years ago, in the construction of
aqueducts, sewers and fountains.
The Colosseum, built by Vespasian and
Titus, A. D. rs to 80 was constructed
largely of concrete walls, in which the
natural cement was extensively used. The
dome of the Pantheon, erected at the
beginning of the Christian era, is Of
concrete supported on a frame work of
brick arches.
It is also known that the Egyptians madea
natural hydraulic cement, and that an aque-
duct seventy miles long was constructed of
concrete and natural cement for the ancient
city of Carthage in North Africa.
The first natural cements made in
modern times was made by John Smeaton
in 1857 and used by him in the construction
Of the famous Eddystone lighthouse on the
English Channel coast south of Plymouth.
The first real artificial cement was made
IN 1924 by Joseph Aspdin, a brick mason
Of Leeds, England. He called the product
Portland cement because the artificial stone
produced from such cement was very SINH
lar in appearancet to the noted building stone
quarried on the island of Portland, in Dor
setshire, England. Portland cement how
ever was not used as a building material un-
til in 1850, an eminent engineer, John Grant,
had persistently advocated it's use.
Natural hydraulic cement was first used
in the United States in 1918 by Canvass
White on construction work on the Erie
canal in New York. In fact canal work in
New York, Pennsylvania, Maryland, Ohio
and Illinois led to the establishment of a
considerable number of natural cement
plants in the above states between 1918 and
1888, many Of which are still in existence.
The first Portland Cement made in this
country vas made by David O. Saylor, of
Coplay, Pa. He was a manufacturer of
natural cement, and made a Portland
Cement in his efforts to improve his
product.
In 1902,-17,23O,6 44 barrels Of Portland
Cement were manufactured in the United
States. A barrel Of Portland Cement
weighs $50 pounds.
IN THE NATURE AND CONSTITUTION OF
DNDrT A1n HrnErHnD
Many eminent Investigators have devoted
much time to this subject, among them
LeChatlier, Clifford Richardson, s. B. and
w. B. Newberry and Zulkowski and
Bleininger.
1t has been we'll established that Portland
Clements are basic slags produced by vitri-
fcation, belonging to the sub-silicate group,
with tri-calcium silicate as the main
hydraulic factor, assisted by calcium alum
mum compounds which are spinel-like in
character. Chemical Investigations have
failed more or less completely to show what
the true nature of Portland Cement is, but
microscopic meteorological examinations
have yielded very good results.
LIE Chatelier states that Portland Cement
consists of, LIST, colorless, Misunderstanding
cubical crystals. which he called alte and
which is tri-calcium %silicate, 3CaO. SiOa and
End Of a darker substance, double refrac-
ting, but without crystalline structure
which he called celtic and which il tri-
calcium illuminate, 3CaO. Al2Os.
These two constituents are the active
elements Of Portland Cement and the settl-
ing and hardening of the Cement is due to
the hydration ii. 9. the chemical combining
with water) Of these two substances. The
following equations express this:
3Cao. 81 Oh so-CasiO.. 2.5 no +
2Ca (OH)a.