p into the earth in order to get rid of all
vibrations on account of the sensitive instruments that were upon it.
There was the Thomson reflecting mirror galvanometer and electrometer,
while nearby were the standard cells by which the galvanometers were
adjusted and standardized. This testing-table was connected by means
of wires with all parts of the laboratory and machine-shop, so that
measurements could be conveniently made from a distance, as in those
days we had no portable and direct-reading instruments, such as now
exist. Opposite this table we installed, later on, our photometrical
chamber, which was constructed on the Bunsen principle. A little way
from this table, and separated by a partition, we had the chemical
laboratory with its furnaces and stink-chambers. Later on another
chemical laboratory was installed near the photometer-room, and this Dr.
A. Haid had charge of."

Next to the laboratory in importance was the machine-shop, a large and
well-lighted building of brick, at one end of which there was the boiler
and engine-room. This shop contained light and heavy lathes, boring and
drilling machines, all kinds of planing machines; in fact, tools of all
descriptions, so that any apparatus, however delicate or heavy, could be
made and built as might be required by Edison in experimenting. Mr. John
Kruesi had charge of this shop, and was assisted by a number of skilled
mechanics, notably John Ott, whose deft fingers and quick intuitive
grasp of the master's ideas are still in demand under the more recent
conditions at the Llewellyn Park laboratory in Orange.

Between the machine-shop and the laboratory was a small building of wood
used as a carpenter-shop, where Tom Logan plied his art. Nearby was the
gasoline plant. Before the incandescent lamp was perfected, the
only illumination was from gasoline gas; and that was used later
for incandescent-lamp glass-blowing, which was done in another small
building on one side of the laboratory. Apparently little or no lighting
service was obtained from the Wallace-Farmer arc lamps secured from
Ansonia, Connecticut. The dynamo was probably needed for Edison's own
experiments.

On the outskirts of the property was a small building in which lampblack
was crudely but carefully manufactured and pressed into very small
cakes, for use in the Edison carbon transmitters of that time. The
night-watchman, Alfred Swanson, took care of this curious plant, which
consisted of a ba