Evening star. [volume] (Washington, D.C.) 1854-1972, 1898-02-09

%. 1897, for the use of the Senate COM
mittee on the District of Columbia This
cations made by Mr. W. c. Allen. inspec-
tor of electric lighting, and a letter from
the superintendent of the naval observa-
tory relating to the effect of the ground
return of electric currents upon the mag
netic observations which have been car
ried on at that observatory. Attention is
also invited to the supplemental report
made by Mr.. Allen under date of February
l, 1898, and to a further statement from
the superintendent of the observatory upon
the conditions existing at that time. Copies
OF these reports are appended hereto.
The Additional Tests.
The report of additional tests made In
the District in relation TO the electroly sis
Of underground pipes and cables by Mr..
Allen is as follows:
The Washington Gas Light Company
have three-inch pipe running from the
Standard Oil Company's works at the
corner of Half and X streets southeast,
through pump and receiving tank at the
corner of 1st and l. streets southwest, to
receiving and overflow Tanks at the inter
section of New Hampshire and Virginia
avenues northwest following the route
shown by red line en- the accompanying
plat. This pipe line is used to convey
naphtha from the Standard Oil Company S
tanks to the works of the gas company
at New Hampshire and Virginia avenues,
when the river is SO blocked with ice that
barges cannot be brought up to the COM
pany's wharf. In December 1897, while
attempting to pump naphtha through the
lire, leaks were developed at Az street
and Virginia avenue southwest, and on
Virginia avenue between Sd and AZ streets.
So great was the leak at the latter point
that considerable naphtha flowed through
the ground and became ignited by match
carelessly thrown by a boy. A fire re-
suited, burning up several panels of the
fence inclosing the tracks of the Balti-
more and Potomac Railroad Company; the
latter company sent bill for damages
to the amount of $500 to the gas COM
pany, which bill has been paid.
Upon eXcavating, the gas company found
two lengths of pipe eaten out, both of
which have been replaced. Figure 1 fs a
photograph Of a section of the pipe taken
from the northwest corner of AZ street and
virginia avenue, showing the hole eaten
out by the current. Figure 2 is a photo
graph OF section of the pipe taken out
from the other location between 80 and Az
streets, where the fire occurred showing
two holes which were directly under two
small water service pipes crossing the oil
PIPE at right angles.
Readings From Pipe Line
The afternoon Of January 4, 1893, the
pipe line at Az street and Virginia avenue
was uncovered and readings taken. Before
unjointing, the oil main was found to be
main; " to l volt positive to the negative
return Of the Potomac Electric Power
Company; 1-3 to II volt positive to the
rails OF the Metropolitan Railroad Com
pany; 1-3 volt positive to the lead cover of
the cables of the latter company. After
Injointing, the difference of potential be-
tween two ends of the pipe was steadily
1 volt toward the west. An ammeter in
serted in series with the pipe line showed
a flow CT amperes toward the west. The
ufar act,
turn of the Potomac Electric Power Com
pany. AT night the conditions changed
considerably, owing to the current from the
latter company's cables. The oil main
changed to % to 31s volts negative to
the return of the latter company. With a
difference of potential between the two
ends of the pipe of from 3ia to volts in
the same direction as before, and with an
increase of current to 6 amperes.
Two days after January g. 1888 the
Oil main was uncovered on Virginia ave-
nue. bt tween 3D. and IA streets and similar
tests made. this time in the presence of
the superintendent of the Potomac Elec-
trio Power Company. In the day time the
oil main was found 1-3 to 1-2 volts positive
to the return of the Potomac Electric
Power Company; 1-3 to IL volts positive
to the tracks of both the Metropolitan
railroad and the Baltimore and Potomac
railroad, and IL to 2 volts positive to
the water service pipes. The difference of
potential between the two ends of the pipe
was IL volts toward the west, with a
flow of 2 IL to amperes. At night the
readings were: Oil main, l volt positive to
waller service, to 1-:S volts negative 10
the return of the Potomac Electric Power
Company, with a difference of l volt be-
tween ends of the pipe and a current Of 6
amperes through it,
Experiments ut Receiving. Tank.
ION the same afternoon tests were made
at the receiving tank of the naphtha at
{,f aP 7
Virginia avenues. The pipe where it en-
tiers the pipe was disconnected and a diff
ference Of 3 1-3 volts found between it and
rent OF ampereS was obtained. The work.
men at this place refused at first to dis
connect the pipe, as they had noticed
sparkling there a few weeks before when
making other connections and were afraid
to work above the tank, which is ten feet
in diameter and ten feet high. and was
full Of naphtha. The joint was bridged
around, however, before breaking ii so as
to prevent any sparkling.
ION the afternoon of January 20, 1885, the
pipe line was uncovered at list street and
Delaware avenue southwest, and the pipe
cut. 1t was found to be 2-3 volt positive
to the water main, with l 1-6 volts be-
tween the ends and current of amperes
toward the north. The pipe was also I'M
jointed at the pump at the corner of LIST
and l. streets southwest where a difference
of potential Of l volt and a current of 2
ampercs were found. No tests were made
at these two points at night.
Conditions Vary.
las the investigation of this case has not
been completed. positive theory can be
advanced concerning it. 1t can be stated,
however, that during the night when the
arc lamps II aintained by the Potomac Elec-
trio Power Company are burning, and con-
siderable current is beiEg sent through
their cables in AZ street that the conditions
in the pipe line materially changed, a
great amount of current being present. The
receiving tank at the corner of LIST and l.
streets southwes st is 20 feet in diameter and
12 feet high. The tanks present large
surface area in contact with the ground,
and, being connected by a pipe line, the
joints OF which are screw joints, and there
fore well connected electrically, form an
easy path for any current seeking a return
through other paths than those provided
for it. The larger amount of current at
New Hampshire and Virginia avenues and
it's flow in a westerly direction toward the
station of the Potomac Electric Power
Company, terd to show that the current
found in the pipe line was generated there.