Evening star., 1926-09-19
CONCRETE UTILIZED
IN ANCIENT ROME
Volcanoes Furnished Mate
rials of Varying Texture
for Building Purposes.
srecial Dispatch to The Star.

Special Dispatch to The Star.
BALTIMORE. September 1s.-Pre-
historic volcanoes provided the ma
terials used in the construction Of the
famous buildings of ancient Rome.
The early Roman builders also used
concrete. according to DIR. Tenney
Fra nix. philologist of Johns Hopkins
University, who recently returned
from Europe, where he spent much
time in Italy and the Roman prov
inces'' gathering data on the economic
history of Rome.
The rock formations underlying the
seven hills of Rome" and vicinity are
the result of volcanic activity in pre-
historic times. The Alban Volcanoes
south of the Tiber and the Sabatini
Volcanoes to the north intermittenty,
belched forth streams of molten lava
and great clouds of ashes. which by
the action Of water were cemented or
hardened into rock.
There are many varieties of these
rocks or "tufas." differing in hard
ness. strength. texture and color, ac
cording to their origin and process of
formation. Some are lava. some hard
ened ash. Eruptions show differences
in character. In the same eruption
differences occur due to the fact that
heavy particles of ash fell near the
point of origin, while the finer parti-
cles were carried to greater distances
by the wind, resulting in stone of finer
texture. In some places the ash has
never hardened. and consequently
was and still is. used extensively in
stead of sand in concrete and mortar.
Quarries Also Opened.
In the early days of Rome ouarries
We're opened and this stone brought
into use. One quarry would be used
until another with better grade of
stone was opened. SO that different
'tufas" had successive periods of
popularity. Thus it is possible aC,
Cording to DR.. Frank. to identify these
''tufas" in the various buildings and
ruins and IN this way formulate a
chronology of Roman architecture.
All these various "tufas" are ugly
and unattractive. varying in color
from dirty gray to reddish brown.
The early Roman builders soon learn
ed to hide their ugliness under a white
plaster or stucco. The extensive use
of concrete or its equivalent in Ro-
man construction. says DIR. Fran nk,
was doubtless due to the accidental
discovery that good concrete could he
made from one part lime TO three
Parts ''pozzolana" or volcanic ash.
NIllc tIe part llfle t'' LNO parts S9 no
was required White sand was scarce
a Rome, and DR.. Frank suggests that
perhaps the discovery came about by
lahorer furtively shovelng cheap
substitute into the mortar pan.
Only One Very Hard.
There was only one of these "tufas"
which. because of its hardness and
fine texture. could h sucre&sfl1llv used
for Inscriptions or for the carved col
umns when the Grecian style of archi-
lecture came into vogue. Lapis AL
hanus. or peperno, in spite of these
good qualities. had to he covered with
plaster to hide it's ugliness
All the time Rome was building with
this unsightiy volcanic rock there Law
at her door. underneath the grassy
plains stretching away to the Sabine
Hills. stone possessing both quality
and beauty. the travertine used in the
Colosseum. and in modern times i'm.
ported for use in the construction of
buildings in New York and Philadel.
phia.
1t is sedimentary rock. deposited
by hot springs during the early part
OF the period OF volcanic activity. Ap-
parentlN 1t was not discovered hy the
Romans until after the middle of the
second century r. c. and was very
little used during the republican era.
The importation of marble for build
into Eogue until the days of Caesar.