locomotive. In fact, the same number of piston strokes per minute may
be preserved in the two modes of running, so as to reduce the speed in
ascending, in proportion to the diameters of the wheels. There will thus
occur the same consumption of steam. On another hand, there is nothing
to prevent the boiler from keeping up the same production of steam, for
it has been ascertained by experience, on the majority of railways, that
the speed of running has no influence on vaporization, and that the same
figures may be allowed for passenger as for freight locomotives.

The difficulties in the way of construction that will be met with in the
engine under consideration will be connected with the placing of the
double wheels, which will reduce the already limited space at one's
disposal, and with the necessity that there will be of strengthening all
the parts of the mechanism that are to be submitted to strain.

The installation of the auxiliary track will also prove a peculiarly
delicate matter; and, to prevent accidents, some means will have to be
devised that will permit the auxiliary wheels to engage with this
track very gradually. Still, these difficulties are perhaps not
insurmountable, and if M. Cottrau's ingenious arrangement meets with
final success in practice, it will find numerous applications.

* * * * *




BACHMANN'S STEAM DRIER.