y William S. Hudson, but before describing his
invention it will be helpful to discuss several earlier attempts to
equalize pony trucks with the drivers.

In 1857 John P. Laird, then master mechanic of the Marietta and
Cincinnati Railroad, rebuilt an old Niles 8-wheeler into a curious 2-6-0
on which only the two rear driving wheels were coupled. The front driver
was driven by a chain and sprocket, and the pilot wheels were equalized
with the front driving axle. The success or failure of the arrangement
has not been definitely determined, but whatever the outcome, Laird
continued his experiments when he became superintendent of motive power
for the Pennsylvania Railroad in 1862. He abandoned the chain drive for
a more conventional arrangement of side rods, but the truck and his plan
of equalization were much the same as that tried earlier. Laird used two
equalizing levers, attached at one end to the front spring hangers and
at the other to the truck, but in a way to allow the truck to swing
horizontally. The fulcrum for each lever was mounted on the underside of
the front frame rail. A number of old 8-wheel Baldwin flexible-beam
engines and several Winans' Camels were rebuilt in this way. One of
these is shown in figure 8. Laird, however, eventually became
dissatisfied with his arrangement and re-equipped the engines with
Bissell trucks.

[Illustration:

LOCOMOTIVE ENGINE SAFETY TRUCK CO.
OF NEW YORK.

Proprietors of the following Letters Patent granted to Levi Bissell,
Aug. 4, 1857, Nov. 2, 1858 (extended Nov. 2, 1872); A. W. Smith,
Feb. 11, 1862; D. R. Pratt. Oct. 16, 1860; W. S. Hudson, April 5,
18[digits missing] and May 10, 1864.

DRAWINGS FURNISHED AND LICENSES GRANTED ON APPLICATION.

A. F. SMITH, President. M. F. MOORE, Sec'y and Agent
ALBERT BRIDGES. Treas. No 46 Cortlandt st. N. Y.

FIGURE 12.--Notice of the Locomotive Safety Truck Company listing the
patents held by it. From _Railroad Gazette_, March 3, 1876.]

John L. Whetstone on April 10, 1860, obtained U.S. patent 27850, which
strikingly anticipated the plan Hudson was to develop four years
later.[22] Whetstone did not use a Bissell truck and was in fact more
concerned in relieving the excess weight, often a 50% overload, from the
front axle of 0-6-0 locomotives and in distributing a portion of that
weight to a pony truck. His arrangement may be readily understood from
the patent drawing in figure 9. Probably the bes