MECHANICAL AND USEFUL ARTS. 23 



entirely upon the possibility or impossibility of the substitution of 

 steam power for the haulage of boats, the author compares the rela- 

 tive advantages of canal and railway conveyance -as regards the 

 transmission of merchandise, and expresses an opinion that if steam 

 haulage could be successfully applied to canal navigation, canals 

 would, in a pecuniary sense, become as valuable as they have ever 

 been. The author proposes to remove the difficulty hitherto existing 

 to the introduction of steam-boats on canals, viz., the washing away 

 of the banks by the swell, by lining the upper part of each side with. 

 coarse rubble stone ; and states that this may be effected by a simple 

 apparatus, without stoppage of the traffic. Presuming the canals to 

 have been prepared for their reception, the author proposes to use 

 steam tugs of horse-power determined by the traffic, and of light 

 draught of water, each of which would haul a flotilla of canal boats 

 dependent in number on the traffic and the power of the engines. 



THE EARL OP CAITHNESS' STEAM CARRIAGE. 



The success attending Lord Caithness' experiment with his Steam 

 Carriage for common roads has drawn general attention to the 

 invention. 



The front view is that of a phaeton placed on three wheels and 

 made a little wider than ordinary, so as to have room for three or 

 even four abreast. The driver sits on the right-hand side, resting his 

 left hand on a handle at the end of a bent iron bar fixed, below the 

 front spring, to the fork in which the front wheel runs, and guiding 

 ■with ease the direction of the carriage. Placed horizontally before 

 him is a small fly-wheel fixed on an iron rod, which, passing downward, 

 ■works at the lower end by a screw through one end of a lever attached 

 at the other end to a strong iron bar that passes across the carriage, 

 and has fitted on it a drag for each of the hind wheels. By giving 

 the fly-wheel in front a slight turn with his right hand, the driver 

 can apply a drag of sufficient power to lock the hind wheels and stop 

 the carriage on the deepest declivities of common roads. Inside the 

 carriage, in a line backward from his right hand, is placed a handle, 

 by which the steam is let on, regulated, and shut off at pleasure. 



The tank, holding about 170 gallons, forms the bottom of the 

 carriage, and extends as far back as the rear of the boiler, where the 

 water is conveyed from it into the boiler by a small force pump 

 worked by the engine. There are two cylinders, one on each side, 6 

 inches diameter and 7 inches stroke. These, and all that is necessary 

 to apply the power to the axle, are well arranged and fitted in so as 

 to occupy the smallest possible space between the tank and the boiler, 

 and appear at first sight insufficient to exert nine-horse power. The 

 coal, 1 cwt. of which is sufficient for twenty miles on ordinary road, 

 is held in a box in front of the stoker, whose duty it is to keep up the 

 fire, sue that there is always sufficient water in the boiler, and that 

 the steam is up to the reepjired pressure, as seen by the gauge on the 

 top of the boiler. 



The power of the engine, and the perfect control his lordship has 

 over it, have enabled him, on several occasions, to make long 



