1885 lamp comparison by the Franklin Institute

[Tim]

Recently I acquired an 1887ish Edison United Manufacturing Co. sales brochure advertising the Edison System including lamps, dynamos, etc. One page of the brochure proclaims that Edison lamps have no equal and a 1000 hour life test was conducted in 1885 by the Franklin Institute comparing various lamps. I thought it might be interesting to share the results here of that test. Of course the Edison lamp wins   The test is based on 1000 hours with the results shown below.

Filament comparison after 1000 hours:

WOODHOUSE & RAWSON,       BROKEN,      ALL OUT OF 11 TESTED
WESTON,                                  BROKEN,      17 OUT OF 24 TESTED
STANLEY,                                 BROKEN,       19 OUT OF 22 TESTED
EDISON,                                    BROKEN,        1 OUT OF 21 TESTED

Percentage of light output lost after 1000 hours:

EDISON LOST 5% OF NORMAL LIGHT OUTPUT
WESTON LOST 65% IN THE FIRST TRIAL
WESTON LOST 30% IN SECOND TRIAL AFTER 500 HOURS, AND 60% AT 1000 HOURS


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-Tim

[This message has been edited by tim (edited September 18, 2000).]

[Bob Masters]

Tim,
That is fascinating information !
It shows how fierce the competition was even in the earliest of years. I'll bet those other manufacturers didn't much care to see those results being published.
Thanks for the info Tim !

Hi Tim, I have a complete copy of that 1885 Report if you would like to borrow it to enter into your data bank. I also have one of the Stanley-Thomsons that were used in that test.