sent day.

XIII. EDISON'S ELECTRIC RAILWAY

AS narrated in Chapter XVIII, there were two electric railroads
installed by Edison at Menlo Park--one in 1880, originally a third of a
mile long, but subsequently increased to about a mile in length, and the
other in 1882, about three miles long. As the 1880 road was built very
soon after Edison's notable improvements in dynamo machines, and as the
art of operating them to the best advantage was then being developed,
this early road was somewhat crude as compared with the railroad of
1882; but both were practicable and serviceable for the purpose of
hauling passengers and freight. The scope of the present article will
be confined to a description of the technical details of these two
installations.

The illustration opposite page 454 of the preceding narrative shows the
first Edison locomotive and train of 1880 at Menlo Park.

For the locomotive a four-wheel iron truck was used, and upon it
was mounted one of the long "Z" type 110-volt Edison dynamos, with a
capacity of 75 amperes, which was to be used as a motor. This machine
was laid on its side, its armature being horizontal and located toward
the front of the locomotive.

We now quote from an article by Mr. E. W. Hammer, published in the
Electrical World, New York, June 10, 1899, and afterward elaborated and
reprinted in a volume entitled Edisonia, compiled and published under
the auspices of a committee of the Association of Edison Illuminating
Companies, in 1904: "The gearing originally employed consisted of a
friction-pulley upon the armature shaft, another friction-pulley upon
the driven axle, and a third friction-pulley which could be brought
in contact with the other two by a suitable lever. Each wheel of the
locomotive was made with metallic rim and a centre portion made of wood
or papier-mache. A three-legged spider connected the metal rim of each
front wheel to a brass hub, upon which rested a collecting brush.
The other wheels were subsequently so equipped. It was the intention,
therefore, that the current should enter the locomotive wheels at one
side, and after passing through the metal spiders, collecting brushes
and motor, would pass out through the corresponding brushes, spiders,
and wheels to the other rail."

As to the road: "The rails were light and were spiked to ordinary
sleepers, with a gauge of about three and one-half feet. The sleepers
were laid upon the natural grade, and there was co