328 Mr David Stcvcnson''s Observations on the 



iron. Sometimes, however, the greater part of the wheels, like 

 the framing, is made of wood. 



It was lately suggested, as an improvement on locomotive car- 

 riages, to work the engines more slowly, and to produce the same 

 or a greater speed by increasing the size of the wheels. Wheels 

 of six feet in diameter were accordingly applied to one of the 

 engines, but were found to produce an unsteady motion, and so 

 greatly to increase the liability of the carriage to start off the 

 rails or break down, tiiat they were immediately discontinued. 

 The Railway Company at present allow no wheels more than 

 five feet in diameter to be used on the line. The greatest speed 

 which the engines have been able to attain on a level, is sixty 

 miles per hour, without a load. The Planet engine with her 

 tender went from Liverpool to Manchester in forty-five minutes ! 

 being at the astonishing rate of forty miles per hour, including 

 time lost in stoppages and ascending the inclined plane. 



During wet weather the engine wheels are found to adhere 

 better to the rails than in dry weather, but if the rails are only 

 damp or greasy^ the wheels have a tendency to slide instead of 

 rolling, and the carriages then have considerable difficulty in 

 dragging along their loads. According to Mr Booth"'s experi- 

 •ments, the adhesion of the wheels, in the most unfavourable state 

 of the rails, is equal to one-twentieth of the weiglit supported 

 by them. During frost, a loaded waggon is generally placed 

 before the engine to rub off any ice or hoarfrost that may adhere 

 to the rails. After the steam is thrown off, and the break or 

 drag applied, in order to stop the trains, the time that elapses 

 before they cease to move, is generally from 40 to 60 seconds, 

 but this depends entirely on the state of the rails, and the rate 

 at which the carriages are moving. 



There are generally eight or ten engines at work on the line, 

 each of which makes four trips a-day between Liverpool and 

 Manchester, and on coming in at night the steam is blown off, 

 and the machinery is thoroughly cleaned. At each end of the 

 line the company have a depot, consisting of sheds, where the 

 engines are i-epaired at the sight of an overseer or manager, and 

 it is not a little remarkable that !^00 men are employed in keep- 

 ing these engines in good order. The carriages are daily in 

 want of some small repair, but they generally run about eighteen 



