what one dollar will buy in different
kinds of light; "table, weight of copper required different distance,
100-ohm lamp, 16 candles"; table with curves showing increased
economy by larger engine, higher power, etc. There is not much that is
dilettante about all this. Note is made of an article in April, 1879,
putting the total amount of gas investment in the whole world at that
time at $1,500,000,000; which is now (1910) about the amount of the
electric-lighting investment in the United States. Incidentally a note
remarks: "So unpleasant is the effect of the products of gas that in the
new Madison Square Theatre every gas jet is ventilated by special tubes
to carry away the products of combustion." In short, there is no aspect
of the new problem to which Edison failed to apply his acutest powers;
and the speed with which the new system was worked out and introduced
was simply due to his initial mastery of all the factors in the older
art. Luther Stieringer, an expert gas engineer and inventor, whose
services were early enlisted, once said that Edison knew more about gas
than any other man he had ever met. The remark is an evidence of the
kind of preparation Edison gave himself for his new task.

CHAPTER XII

MEMORIES OF MENLO PARK

FROM the spring of 1876 to 1886 Edison lived and did his work at Menlo
Park; and at this stage of the narrative, midway in that interesting and
eventful period, it is appropriate to offer a few notes and jottings on
the place itself, around which tradition is already weaving its fancies,
just as at the time the outpouring of new inventions from it invested
the name with sudden prominence and with the glamour of romance.
"In 1876 I moved," says Edison, "to Menlo Park, New Jersey, on the
Pennsylvania Railroad, several miles below Elizabeth. The move was due
to trouble I had about rent. I had rented a small shop in Newark, on the
top floor of a padlock factory, by the month. I gave notice that I
would give it up at the end of the month, paid the rent, moved out,
and delivered the keys. Shortly afterward I was served with a paper,
probably a judgment, wherein I was to pay nine months' rent. There was
some law, it seems, that made a monthly renter liable for a year. This
seemed so unjust that I determined to get out of a place that permitted
such injustice." For several Sundays he walked through different parts
of New Jersey with two of his assistants before he decided on Menlo
Park. The