The midland journal. (Rising Sun, Md.) 1885-1947, 1899-08-18
ELECTROLYsIs OF PIPES.
An Industrial Problem That Is Just
Now Puzzliug the Engineer
ing World.

"Electrolysis constitutes one of the
very greatest industrial problems of the
present day" said Guy NJ. Gest, of Phil
adelphia, the conduit expert, who su-
perintended large part of the recent
work in New Orleans. Il reSer to its
action on underground piping, particu
larly water mains. 1t is threatening
scores of water systems throughout the
country with total destruction and is
causing the gravest apprehension
among the large fire insurance COM
panies. The worst of it is that in spite
of the efforts of some of the most emf
ncnt electricians of the world no rem
cdy has as yet been discovered" This
statement will be a surprise to the aver
age reader, who has only vague idea
of what electrolysis really is. Roughly
explained, the term is applied to the
dissolving or erosive effect of electric
currents under certain conditions.
For example, a current Jumps" from
a trolley car track to a water pipe. At
the point where it enters the piping
curious process of disintegration usual
ly sets in. 1t is almost exactly like the
action of a powerful acid. In short
time the metal becomes honeycombed
with minute pores, which grow larger
and larger until the spot affected gives
way like 4 piece of rotten wood Some
of the large mains taken out in different
cities present most remarkable ap-
pearance. They look like sections of
petrified sponge and can be pounded
into powder with q tack hammer. The
rapidity of the destruction varies ac-
cording to laws not thoroughly under
stood. Sometimes it is very slow and
the mischief is the work of years;
again, under current Of precisely the
same power, q solid iron main three
inches thick will be eaten through and
through in few months. Mr.. Gest
cited an instance Of a service pipe at his
home Office which he was obliged to re-
new six times in one year.
The currents that cause the trouble
come, nearly always, from trolley lines.
Theoretically, the electricity drawn
down from the overhead wires and in
propelling the cars is supposed to re-
turn to the power house through the
rails. But electricity, like everything
else in this world, moves in lines of the
least resistance, and sometimes the
rails become overloaded. In such a case
the current is apt to jump to any bet
ter conductor near at hand and con-
tinue on its journey, and usually that
conductor is water pipe. With the
customary ingratitude of nature it re-
pays the service by destroying the bor-
rowed right of way. The route of some
return currents, as traced by the disas-
trous trail of electrolysis, is frequently
very curious. They will travel for a
block or two on water main, then
jump to gas main, then back again to
some cross section of a water pipe, and
finally return to the rail, always head
ing for the power house, like homing
pigeon. AS all this goes on beneath the
surface of the ground the first intima-
ton to the public is generally the burst
ing of a main, which almost always oe-
ours when extra water pressure Is put
on for fire. Hence the imminent dan
ger. Great confagrations have oc-
CURED in several large cities during
the past year because rotten pipes
burst at the critical moment and the
firemen We're suddenly left without
water. In such places the work of
patching is continual, but there is never
any telling when the trouble will break
out in a new spot.-N. o. Times-Demo-
crat.