c. Whether one or two men would be required for the management of the
engine.

As regards these preliminary special points, the compressed air motor, as
well as the Rowan engine, required to be turned for the return journey,
whereas the other motors could run in either direction.

In regard to this, the electric car was peculiarly manageable, as it
moved in either direction, and the handle by which it was managed was
always in front, close to the brake. This carriage was the only one which
was entirely free from the necessity of attending to the fire during the
progress of the journey, for even the compressed air engine had its small
furnace and boiler for heating the air.

Each of the motors under trial was managed by one man.

The several conditions of the programme may be conveniently classified in
three groups, under the letters A, B, C. Under the letter A have been
classed accessory considerations, such as those of safety and of police.
These are of special importance in towns. But their relative importance
varies somewhat with the habits of the people as well as with the
requirements of the authorities; for instance, in one locality or country
conditions are not objected to which, in another locality, are considered
entirely prohibitory.

The conditions under this head are:
1. Absence of steam.
2. Absence of smoke and cinders.
3. Absence, more or less complete, of noise.
4. Elegance of aspect.
5. The facility with which the motor can be separated
from the carriage itself.
6. Capacity of the brake for acting upon the greatest
possible number of wheels of the vehicle or vehicles.
7. The degree to which the outside covering of the
motor conceals the machinery from the public, while
allowing it to be visible and accessible in all parts to
the engineer.
8. Facility of communication between the engineer
and the conductor of the train.

In deciding upon the relative merits of the several motors, so far as the
eight points included under this heading are concerned, it is clear that,
except possibly as regards absence of noise, the electrical car surpassed
all the others.

The compressed air car followed, in its superiority in respect of the
first three points, viz., absence of steam, absence of smoke, and
absence of noise; but the Rowan was considered superior in respect of the
other points included in this class.