The Washington herald. [volume] (Washington, D.C.) 1906-1939, 1909-02-23
HIGH PRESSURE GAS.
New Policy In the Distribution OF
the IIIuminant.

Prom the Literary Digest.
The policy OF distributing gas at high
pressure, now being adopted by many
companies. has sons interesting features.
coming, IS It does. together with the
great increase in electric voltage on trans
r''issinn lines High pressure. whether
gaseous or electrical. has It's advantages
and its disadvantages. but the FORMER
are now generally considered TO outweigh
the latter. Says a writer IN cosmos
Paris:
installations OF high-pressure gas are
becoming numerous in America The
principal advantage Of the system is the
smaller size Of eoHduits, which is also
indirectly advantageous because small
pipes can be made very strong and al
most absolutely tight. In this way a
powerful central station may serve nj
merous localities. including places too
small 10 have separate plants.
The high-pressure system at san Fran
cisco uses the heavy petroleum oils OF
the region, by distiIlation. Dir. Z {.
Jones. the creator Of this plant. OF which
he has had charge since 1905. has taken
special care to make the joints tight
Although the number Of leaks due 20 the
high pressure has increased, he estimates
that the actual loss OF gas is less than IN
other plants.
IN a distribution where the pressure is
normally twenty millimeters {four-fifths
inch) OF water. and never exceeds 50 MILL
meters 1.-TWO and One-hfths inches, leaks
may exist for z long time without giving
signs Of their existence; the gas is lost
IN the intsrs;ices OF the ground, or &C.
cumulates az certain points. II leak IS
sought, the test-paper gives its character
istic reaction along a length Of hfty
meters O65 feeD. without indicating any
point exactly; or the paper may react only
al a great distance from the leak OF
again. long after the leaks have been
stopped the gss-satUrated soil may
blseken the paper.
"On the other hand. in plans where, as
In the suburbs Of San Francisco, the
pressure varies from 700 70 z.l00 grams q
the square centimeter. or 10 q meters
% 10 So feet Of water. every leak mani
tests itself az once.
The delivery OF Illuminating gas 81
high pressure has also thrown light on an
interesting Industrial problem The laws
that govern the compression OF mixtures
Of gases and vapors enable US 70 foresee
a diminution Of the Illuminating power OF
the gas, due 20 liquefaction OF the Ign;
hydrocarbons. Experience confirms tnis
view but no simple laws have been dis
covered for calculating the loss az a given
pressure.
The condensed liquid that Is collected
IS composed OF water, uaphthaIln, and
some benin, and tolaol or benzol. This
benzol IS the product that gives the gas
fame most Of its Illuminating power For
merly gas-makeTs attempted 10 produces
il with the gas and TO preserve it, or ever
10 add more. to enrich the gas. To-day,
with the general use Of incandescsu'
nantes. II suffices 70 give the gas a high
heating power; its fame may even be de-
prived altogether OF free carbon. and mag
consequently give but a feeble light Of
itself Nevertheless, at san Francisco
where the contract requires certain per
CentaEe Of benzol. it has been found easy
10 add this constituent 10 the gas.
IF the pressure is increased still fur
the-. We finally obtain 4 gas deprived not
only OF all the hydrocarbons. both ligh'
and heavy. OF the aromatic series. but
also Of its sulphur products. Here we
have a new plan that may lead 70 consid-
cradle simplifcauon IN the physical meth
DDS Of purifying Illuminating gas IN par
ticular. We may conveniently get rid 1T
this way OF the naPhthslin, which, by OBJ
structing the pipes. Is a continual source
OF trouble