Grand Rapids herald. [volume] (Grand Rapids, Mich.) 1892-1959, 1892-06-03
NOT A FULL LIGHT
Prof. carhart Reports That the
Electric Lamps
ARE NOT UP TO REQUIREMENTS
The Results Of HIS Test maoe Knowa -
the Lamp COMMITTEES q she coun-
cil--Reguia1 noeslnxs-


The committee on lamps consideso1
the report made By Prof. Carhast -
the power OF the electric isghts- rrof.
CsThart's bill wax $Sl.ss aud kis report
% far has served only 20 produos :
lively spat between the oommltsss aa1
the Electric Light 4 Power company.
Manager Hayward claims that ~
professors examination vas made un-
der unfair conditions- II - - follows;
nave tue honor TO ounmie
the following report Of the tsoee
made on the electric hghtlng Dy are
lamps Of the streets of Grand Rapi6a.
Mich, on the evening OF Nay Is, loo3,
between the hours OF 8 ana 10 o'clock.
These tests were made ~ the author
ity Of the lamp oommsttse, and were
intended TO ascertain whether The
energy expended in lighting the lampo
Was OF the proper amount TO outitlo
them TO be called 1900 candle power
lAmpe."
Its well known in the ars Of light
ing by electric arc lamps thas 700
standard candles 10 IN excess Of the light
that can actually lie obtained from =
normal ten smpere lamp. ave undee
the very exceptional oondiuoue of
special carbons. Of the best angle of
elevation OF the lamp from which
maximum ILLUMINATION can b Oh
tanned, and OF an electric pressure he
tween the two separated cartoons ot
about fifty voits. This last item " not
exceptional except IN combination VIII
the other two.
ats Maks-shtfs.
The expression s.2 900 candle power
has therefore come 70 be q commercial
term applied TO good Arc lamps properjy
adjusted, supplied with hrst ciass car.
bons OF the standard slse or slzea, aud
fed with . current OF ten ampeEoe,
under IN electric pressure or dinW.
enoe of potential between the separated
carbons Of from forty-hve 10 nifty voits
each.
The power consumed or expanded %
each lamp 10 then found by multiply
ing together the current and electric
pressure. Thus. 10 times Is equals 80
watts, or 10 tunes SO equals 500 Watts-
The watt 10 . email unit Of power
of which 746 are required TO make one
horse power.
Eacn 1000 candle power lamp should
have then from 45u 70 500 WAtte Of
power expended on it, that 10, from
three-fifths TO tWo-thlrds Of . hosoe
power actual on each lamp. rhn doee
not include the power Lost in hsetane
the line wire nor the losees due 70 t6o
dynamo machine becauee Of - failure
20 convert all OF the mechanical eno1.y
applied TO il into energy il the form Of
an electric current In arc light inoula-
tions il 10 customary 10 reckon one
horse power for every 1000 cao1bo
| power lamp. burnlng under the otAod-
| ard conditions described above. Eoe
Iens. than three hfshs. % two-thtrGo
Of this shouid he actually expepded u
| the electric arc Of the lamp itself.
So much of general statement 10 nec-
| essary 20 explain Why meaeuremeneo
| of current and voltage at the iampo
we're made instead OF candle power Of
the Tampa. 6s
Msaasrsness ss cssrssa
For the purpose of measuring he
current IN amperes . loop was rua
from . pole on Grandvllls avenue into
the Office Of -four and feed store, anl
there by n,eaue OF an appropriate loop
switch an ammeter was pat IN circuit.
| This ammeter WAS made By Carpentsef
| Of Paris and had been carefully cali.
brated in the physical laboratory Of
the University Of Michigan by compaf-
ison with the etandaru lnetrumen>G
used there. The current VA red
every ten minutrs by my assistant froO
7:5S TO 1915 O'Clock on the evening
stated above. The following ere The
readings taken;
Hour, 7:s5, e.s; SOS, e.s. sis. "a;
SIS, 81; s.35. 81; s:l5, a.7s, SIS. 81;
COS, 9.75: e:i5. 81, p.25, 81: ss35, . 6;
a:45, s.75, e:s5, s.75: 1905. s.s; lol5, -;
average, ga.
Measurement es voltage es Pressure
For the measurement Of The elec1rto
pressure between the lamp termsna>S
/ used q standard Weoion volt suooof,
brated in the physlcai laboratoFy o& TIE
university. lie resdiues are fsace,oo
of volt too high. but no deductsoDl
from the apparent rsadines were n,n1o
I in the observations following
The Tampa were lowered end ~
wires leading 10 the volt meter were
connected 20 the terminals Of the lamp
with the following results.
Lamp No. 1, corner williams o0o
South 1ouia streets. - 70 ~ voits; lamC
No. 2, corner Oak and Sheldon esreeoo,
81 20 81 volts; lamp No. 3. corner Enol
Fulton and lafavette street,, e % &
volta, lamp No. 4. corner Fountaio ~
Lafayette streets. Is 70 q volta, iaUr
No. 5. corner Fact Bsdeo and Clin1oG
streets. 70 10 - volts; lamp No. 8. o0f-
ner Broadway and Third ofFee1As j. q
81 volta.
This last lamp was not feeding dewu
lie carbon properly and the arc -
flaming"
Il viii be observed thas fou>
out of the ax inmps me1o
ured were burning - pfee
sure from q PET cent 70 q
per cent h<iow the normal evefnGl
pressure Of as volts pr lamp ~
qsired for . standard 2,eoo ceoGG
| power lamp.
Al the same time the svefaes sne
rent on the iine tessed was . Re1)e u
escsss Of 81 amperes. snetend - -
amperes ~ a should hsVe beeD.
These lamps tested were not 49,
tionsi Tampa. J go many la0pn -
those and spDe even poorer. n
tower Ispspe were not scneuoils1e. 81
tberefore only the Hlow dcWu" sSmr1
were tested In some cneea. - DopkeS1
down . street u vas alsBosf Anpnoo1111
10 tell. escepf ~ relotfve hoi011
which light wss 3 ssseet lamp -
which was ths beafliebf Of 3 49,
cat. some ol the lamps ctoarvu1.
/ venture 20 sf5rm, were nul Rie11|
light m escess Of from 80 - - 60
dard candles.
Ia the CASE Of lampe bufuiue g &
| per cent % ~ re. cenf kr}ow ~ -