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

ent difficulty. keSpecuuIy,
f. b. Rosa,
Acting director.
REPORT OF TEST OF An ARC LAMP FOR
THE CITY OF ALEXANDRIA, VA.
The lamp submitted is Fort Wayne
Electric Co. alternating current en-
closed arc lamp intended to operate on
ALB ampere series circuit, and 1t was
submitted 10 this bureau by direction
OF the mavor OF Alexandria to ascer-
tain whether it could be fairly con
s;dered 10 fulfill the conditions OF al
contract between the city Of Alexandra
and the Alexandria Electric Company,
i'm which it is stated that the arc lamps
shall be of 'the latest type enclosed al
ternatino current arc lamps OF Z,OOO
candlepower. This contract was made
ON August 9, 1906 A 1000 candle
mower arc lamp rs the term has here
tofore been used. is not a lamp which
actually gives 1000 candlepower meas
ured in some particular way, but Is
nominal rating originally applied 10
90 ampere direct current series, open
arc lamp. 1t is unfortunate that
contract made as late as 1906 should
have described lamp as of 1000 can
dlepower without further description
or specification as to what was
meant. Inasmuch as this Is not
nrec;se designation of lamp and
has given rise to misunderstood
inc and dispute. If the city had
counseled with a competent expert at
the time the contract was made, tins
EXPRESSION would not only have been
eliminated, but precise specialization oil
the lamp would have been substituted.
The contractor would then have furnish
ed a lamp at the outset which would
have fulfilled the speciiicatlC and the
present difficulty might have been
avoided However, If we interpret the
contract as requiring an alternating
current enclosed arc lamp, that Will
give a street illumination substantially
eouiyalent 10 that Of the old open arc
which had been commercially rated at
1000 candlepower, that conld be met by
a lamp taking 10 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 i'm Alexandria, and also
from the statement mt our office OF the
representative Of the company, that the
lamps originally installed were 90
ampere lamps. These clearly did not
fulfill the conditions OF the contract
The lamp submitted to vs. Is not how
ever. a &C ampere lamp as 1t refuses to
burn when the current of GO amperes,
ar even a somewhat higher current, Is
used. but it does burn steadily and
regulates we'll on 7.5 amperes. 1t is
therefore perfectly clear that the lamp
is 3 ampere alternating current en-
closed are lamp. However, the lamp
as brought TO our laboratory was not
exactly adjusted. The check II It which
determines the tension on the spring
regulating the length Of the arc was out
of place, and the voltage on the lamp
AS thcs adjusted WIS about 10 volts too
low. Upon proper adjustment the
lamp burned as it should at about II
volts at the terminals OF the lamp. 1t
is possible that some of the lamps in the
circuits i'm Alexandria are out Of adj
iustment in the same particular, e.
that although they are receiving the
full current, the voltage on the lamp
NAV be insufficient. We therefore
suggest that all these lamps should be
examined and put into adjustment
with the help Of vOltmeter, to show
the voltage on the terminals of the
lamp when 1t is burning steadily.
Inasmch as the question has been
raised as to whether the lamps are
properly adjusted we suggest the ad
vantage of having a representative of
the Fit. Wayne Electric Works come to
Alexandria and personally attend to the
adjustment of the lamps, and at the
same time TO give any necessary in
suuctions to the lamp trimer and to the
tepairman OF the Alexandria company,
so that they shall be fully competent
TO keep the lamps in adjustment IN the
future. We suggest further that the
FIT WAYNE Electric Works shall give
TO the CITY OF Alexandria certificate
statlng mat TIE l4nps AdNc pech piVl
hauled and put in adjustment, and that
they are in first class condition.
We also suggest that the city OF
Alexandria employ an electrical expert
skilled as to the construction and use OF
arc lamps and experienced in out Of door
arc lighting, TO inspect the system on
behalf of the city once in three months,
and to report to the city the condition
in which he finds the system. Such an
examination and report could probably
he secured at cost not exceeding 800
ner wear. and would be OF great value
70 the city in furnishing assurance that
,be contract is being observed, and in
avoiding misunderstanding and diff
cnIty in the future. Such an expert
conld also advise the city from time to
time as to the changes in the dlstrhu-
ion of the lamps, OF as 10 the snbsti-
,,,t;nn of other forms OF lamps for street
Ighting. such, for example, as series
Tungsten lamps, which in certain places
I'll ha oreferable 10 these arc lamps.