St. Paul daily globe. [volume] (Saint Paul, Minn.) 1884-1896, 1894-08-20
ASPHALT FOR STREETS.
PECULIAR BEDS IN WHICH
BITUMEN Is FOUND.
An Interesting Story of How ]
Is Prepared Before Use in
Paving.

just now as paving material, IS the
first cousin of the bitumen in which the
Egyptian mummleS of centuries ago
were wrapped for embafming and which
has from time 10 time in history served
variety of ends, says writer in the
st. Louis Post-Dispatcht Sometimes
the early warriors wrapped balls OF
fiber with bitumen, and. igniting it,
used it with deadly effect upon the
enemy. Sometimes il was applied as a
gum or cement, which, after years,
would harden and stiffen into an almost
inn -ishable binding.
The asphalt of today is closely akin
to the bitumen of history. 1t is found
near the Dead sea and in various Sec
tons of Africa, Asia and extreme
Southern Europe. 1t seems to have a
fondness for tropical regions, and fol-
lows along the lines of volcanic relics
and small islands which seem fit for but
little else.
The asphalt which Is now being used
by tons and hundreds of tons for street
paving is nothing more nor less than
natural pitch in various stages of purity
anu IeHllSincut, dilu 10 lOuHu WiLulu d
very small area just along the north
edge of South America. There are de-
posts of natural pitch or as phalt inthe
northern parts of North America and
Lower California, notable New Mexico,
but none of them seem to be of the same
quality and extent as those which
border the northern edge of South
America about 10 deg. above the
equator. Those elsewhere seem to be
of earlier date and are now about dried
and hardened TO such degree that at
supply points they are practically OF no
value unless some new application is
found for the hardened and degenerated
deposits.
The present supplies are in lakes and
pools, which are certainly unique in
their character, as they are closely as
ISOLATED with petroleum and gas. They
will not remain level OH the surface and
have marked aversion to mixing with
water. Even while soft and gummy
under tropical sun this curious deposit
can be broken off in chunks by sudden
sharp blow, and again, if boy stands
upon il too long, it requires good deal
of main strength and hauling to get him
out.
The asphaltum lakes are in some
places very much like the craters of eX-
tinct volcanoes and seem to be the last
efforts of exhausted nature. They all
contain more or less gas, whichis hidden
away in the substance itself in blow
holes, they might be called, like the
holes in Swiss cheese. The pitch itself
is constantly generating gas i'll its natur-
al state, as was found when upon one
occasion samples were being sent to
Washington from South America in
sealed tins, every one of which exploded
with more or less violence while being
transported.
Beside the immense deposits of what
is called lake asphalt, there is another
kind called land pitch. which seems to
be made of Overtiows from the lakes
and from independent upshootings.
which are now covered and surrounded
with soil and dirt and oftentimes mixed
with foreign substances. This may in
time be applied successfully for COM
mercial purposes if processes cheap!
enough can be found whereby to restore
1t 10 something like its natural state. 81
One OF the asphalt lakes just north Of
Bermudez was described in 1855 by.
Mr.. n. s. MaurOss. who says: 60
The channels are produced and
maintained by a singular process. Each;
of the many hundred areas into which
the lake is divided possesses all indie
pendent revolving motion in this wise:
In the center of the area the pitch is
constantly rising up-not breaking up
in streams, but rising up en- masse. 1t
is thus constantly displacing that which
previously occupied the center and
forcing 1t toward the circumference.
Another curious proof of it is afford
ed by numerous pieces of wood. which,
being involved in the pitch, are con-
OF n
are often several feet in length and five
or six inches in diameter. On reaching
the surface they generally assume an
upright position, one end being detained
in the pitch while the other is elevated
by the lifting OF the middle. They may
be seen at frequent intervals all over
the lake, standing up to the height of
two or even three feet. They look like
stumps of trees, protruding through the
pitch, but their parvenu character Is
curiously betrayed by ragged cap of
pitch, which Invariably covers the top
and hangs down like hounds ears on
each side.
"On ascending the last slope of this
pitchy glacier a singular scene meets
the eye. A black and circular plain of
pitch half mile in diameter lies flush
with the edge of the stream. 1t is sur
rounded by dense wall of forest in
which various species of tall palms are
most conspicuous.
1.-The lake itself is entirely bare of
vegetation, except about twenty small
eiamps of trees, which are arranged i'm
sort of broken circle about half way
from the center to the circumference.
ION a closer inspection the entire
surface of this circular plain is seen to
be intersected by network of water
channels. Its appearance is exactly
that of marbled paper. The pitch is
divided into fiat or slightly convex
areas, mostly polygonal, but sometimes
circular. They vary from one to eight
rods In diameter. The intervening
spaces are full of water.
1.-The conclusion then 10 which a close
observation leads us in regard to the
present condition of this singular lake
is, not that it has suddenly cooled down
from boiling state as heretofore de-
scribed, but that, solid as the material
is, if is still boiling, although with an
indefinite slow motion. As the descent
of the glaciers may be considered the
slowest instance of flowing In nature, so
the revolutions of the scarcely less solid
bitumen of this lake may be set down as
the Slowest example of ebullition." rEs1
As to the chemical constitution, of
= 70
asphalt paving. says:
"All asphaits are partially soluble in
alcohol. totally or partially IN ether, and
totally in chioroform and bisulphide or
carbon. By the relative solubility I'M
these solvents we gain important infor.
nation in regard TO the quality of as
phaltS under examination. AsphaltsG
are generally composed of three differ
ent hydrocarbons: First, refine; see
ond, petrolene; third, asphsltene.' mol
The refining process is very simple,
and varies with the purity of the natiV
ural or crude pitch as it is taken out. q
There are several processes which are
in vogue and differ according TO the
product. The sole purpose being to ex &c
tract the foreign material. The after
preparation for paving purposes is very
simple. Sand, stone dust and pulyer-
lied carbonate of lime, in various GUAM
tities,are put III so tina! nice InusilS ,,aste
is the result, which. when ser nor.
can be spread upon almost "a ut
a foundation, and allowed loo liter
1t has been given sprinklins ,f fine
sand and good rolling with :, t,vantv