Alexandria gazette. [volume] (Alexandria, D.C.) 1834-1974, 1910-07-12
E. b. Rosa,
Acting director.

r.. II. hOSSa,
Acting director.
REPORT OF TEST OF An ARC LAMP FOR
THE CITY OF ALEXANDRIA, VA.
The LAM p submitted isa Fort Wayne
Electric Co. alternating current en-
closed arc lamp intended to operate on
AIS ampere series circuit, and 1t was
submitted TO this bureau by direction
of the mayor OF Alexandria to ascer-
tain whether it could be fairly CON
sidered to fulfill the conditions OF a
contract between the city OF Alexandria
and the Alexandria Electric Company,
in which it is stated that the arc lamps
shall be OF the latest type enclosed al
terpatins current arc lamps of 1000
caudlepower. This contract was made
on August 9, 1906. A 1000 candle
power arc lamp rs the term, has here
tofore been used. is not u lamp which
actually gives 1000 candlepower meas
ured in some particular way, but is a
nominal rating originally applied to a
90 arnpere direct current series, open
arc lamp, 1t is unfortunate that a
contract made as late as 1916 should
have described lamp as OF 1000 can
dlepower without further description
or specification as to what was
meant. Inasmuch as this is not a
precise designation OF lamp and
has given rise to misunderstanding
ing and dispute If the city had
counseled with a competent expert at
the time the contract was made, this
expression would not only have been
eliminated, but a precise specification OF
the lamp would have been substituted.
..Tbe contractor would then have furnish
ed a lamp 1T the outset which would
have fulfilled the specifications, and the
present difficulty might have been
avoided. However, if we interpret the
contract rs requiring an alternating
current enclosed arc lamp, that Will
olive n street illumination substantially
eo,,ivalent TO that OF the old open arc
which had bee II commercially rated at
1000 candlepower, that could be met by
y lamp taking rs ampere alternating
current at about II volts At the terml-
nails of the lamp. 1t appears from the
evidence submitted in the hearings that
have been held in Alexandria, and also
from the statement ut our office oil the
representative Of the company, that the
lamps originally installed were &c
ampere lamps. These clearly DID not
fulfill the conditions Of the contract.
The lamp submitted to Us is not, how
ever. &. Is ampere lamp as it refuses to
burn when the current OF 6.6 amperes,
or even somewhat higher current, is
used. but it does burn steadily and
regulates well on rs ampcreS. 1t is
therefore perfectly clear that the lamp
is rs ampere alternating current en-
closed arc lamp. However, the lamp
rs brought to our laboratory was not
exactly adjusted. The check nut which
determines The tension on the spring
regulating the length of the arc was out
of place, and the voltage on the lamp
as thus adjusted WINS about 10 volts too
low, Upon proper adjustment the
lamp burned rs it should ut about "a
volts ut the terminals OF the lamp. !,
is possible that some Of the lamps in the
circuits in Alexandria are out OF adj
justment in the same particular, i. e.
that although they are receiving the
full current, the voltage on the lamp
may be Insufficient. We therefore
suggest that all these lamps should be
examined and put into adjustment
with the help OF Il voltmeter, to show
the voltage on the terminals OF tbs
lamp when it is burning steadily
Iriasmuch as the question has been
raised as To whether the lamps are
properly adjusted we suggest the ad
vantage OF having representative o.
the Fl. Wayne Electric Works come tc
Alexandria and personally attend to the
adjustment of the lamps, and at thu
same time to give any necessary in
structions to the lamp irimer and to thu
repairman OF the Alexandria company
so that they shall be fully competen
to keep the lamps in adjustment IN thu
future. We suggest further that tn
TT. wayne ElcCtIN WINS Siiah sh'
to the city Of Alexandria q ccrtlticat
stating that the lamps have been over
hauled and put in adjrstmcnt, and tina
thew are in first class condition.
We also suggest that the city c
Alexandra employ an electrical exper
skilled as to THE construction and use o
arc lamps. and experienced in out OF doc
arc lighting, TO inspect the System OF
behalf of the city once in three months
and to report to the city the condition
in which he finds the system. Such al
examination and report could probabl.
be secured ut 4 cost not exceeding $40
ner wear. and would be OF great valu
to the city in furnishing assurance tina
the contract is being observed. and il
avoiding misunderstanding and diff
cnlty in the future. Such an exper
could also advise the city from time t
time as to the changes in the distrihu
ton Of the lamps, or as TO the subst1
hilton Of other forms of lamps for stree
lighting. such, for example, as serle
Tungsten lamps, which in certain place
!, ia ha ,raferable to these arc lamps