470 



MOTOR CARRIAGES. 



mixture. A form of aspirating carburetor, in 

 which the gasoline is sucked up in a fine needle- 

 like jet and sprayed in the midst of an inrushing 

 current of air, is the one in most common use. 



The extremely high temperature accompanying 

 the explosions, and the frequency with which these 

 take place several hundred a minute results in 

 greatly overheating the cylinder walls, and necessi- 

 tates the use of some cooling device, usually a 

 water-jacket, and a small pump to maintain the 

 circulation of the water around the cylinder and 

 through a coil of pipe exposed to the air, where it 

 dissipates tin- heat acquired from the cylinder. 



The ignition of the explosive mixture may be 

 effected by an electric spark or by the hot-tube 

 method. In the spark method an induction coil is 

 employed to force a spark at the proper instant be- 

 tween two conducting points or electrodes in the 

 explosion chamber, surrounded by the mixture of 

 gas and air. This of course necessitates carrying 

 a source of electrical energy, which is usually in 

 the form of two small cells of dry battery. In the 

 hot-tube method of ignition the chamber is fitted 

 with a small platinum tube projecting outward 

 therefrom and kept at a high temperature by a 

 gasoline burner placed beneath. The vapor filling 

 the chamber and the interior of the tube comes in 

 contact with its heated sides, which, however, are 

 not at a temperature high enough to ignite it under 

 the conditions of pressure obtaining. As the piston 

 returns the gas is compressed, and at the point of 

 greatest compression that is, at the end of the stroke 

 the temperature of the tube is sufficient to explode 

 the mixture. This apparently crude device has 

 been used with great success on many carriages. 

 The French racing carriages are almost all pro- 

 vided with hot tubes. As will be seen from a con- 

 sideration of the events taking place in the cylinder 

 of a gas engine, this motor can not be self-starting 

 like a steam engine, but some artificial means of 

 previously compressing the gas before an explosion 

 can take place must be used. This is ordinarily 

 effected by turning the engine over once or twice 

 through the medium of a hand wheel. 



The advantages of the gasoline engine consist in 

 the cheap, compact, common, and well-known char- 

 acter of the fuel. At a price of 10 cents per gallon 

 for gasoline, a well-built carriage with two passen- 

 gers should be run at an expense of less than half a 

 cent a mile. 



Electricity as a Motive Power. The electric 

 carriage makes use of electricity stored in the form 

 of chemical energy in accumulators or storage 

 batteries. A storage battery consists of a positive 

 plate containing lead peroxide and a negative 

 plate of porous lead immersed in an electrolyte of 

 dilute sulphuric acid. This combination forms a 

 type of battery which can be discharged in the 

 same way as the ordinary primary cell, and acts on 

 exactly the same principle: and when discharged, 

 either fully or partially, the battery can be con- 

 nected to a source of electrical energy, and the 

 chemical compounds upon the plates, resulting 

 from the passage of the discharge current, trans- 

 formed into their original constituency by forcing 

 an electric current between the plates in a reverse 

 direction. If this reverse current is continued suffi- 

 ciently long, all the active material of the battery 



becomes reconverted to its original chemical form, 

 and the battery is said to be charged, for it is now 

 again able to yield current to the extent of its full 

 capacity, and this process of charge and discharge 

 may be carried on indefinitely. It is evident that, 

 although electricity is put into the cell and later 

 withdrawn.it is really a storage of chemical energy 

 which is effected, which on discharge is manifested 

 as electricity. 



Although the principle of the lead storage bat- 

 tery has been well known since 1860, it is only 

 since 1890 that its increasing fields of usefulness 

 and extended application to the industrial arts has 

 demanded due attention to improvements and re- 

 finements in its manufacture. Stall more recently 

 the peculiar conditions of road-vehicle service have 

 demanded a form of lead storage battery which 

 should possess, among other essentials, lightness 

 and durability; but already storage batteries un- 

 available which conform sufficiently to the require- 

 ments to make the electric vehicle both serviceable 

 and commercially practical. The immense supe- 

 riority of control and the simplicity of the motive 

 power in electric vehicles, have, in fact, a strong 

 tendency to extend this field beyond its most ad- 

 vantageous limits, and to produce a willingness U. 

 accept relatively low standards of performance in 

 storage batteries. 



The relatively poor character of American roads 

 has greatly retarded, and, up to the present time, 

 almost prevented, the introduction of types of auto- 

 mobiles whose principal recommendation lies in 

 unlimited radius of action, and it is not surprising 

 that the world must still look to France as a leader 

 in the production, if not also in the degree of de- 

 velopment, of gasoline vehicles, while in England 

 possibly the extreme conservatism may account for 

 the fact that such development as has been made 

 in that country in the new art has been along the 

 lines of the steam carriage. 



The character of most city streets in the United 

 States has permitted the development of a demand 

 for the electric vehicle, and as a consequence we 

 find the old house of the Pope Manufacturing 

 Company pre-eminent in this particular field. A 

 special form of motor on these vehicles reduces all 

 noise to a minimum. The controller handle, placed 

 conveniently at the left of the operator, gives three 

 speeds through the medium of a very simple con- 

 troller. The steering handle, placed at the right, 

 of the driver, and a foot lever operating a powerful 

 and quick-acting band brake, complete trie appa- 

 ratus necessary for a thorough control of the car- 

 riage. For the average person, but a few hours' 

 trial is necessary to give skill and familiarity in all 

 phases of the operation. A mileage of 30 is the 

 normal amount for these vehicles, although much 

 more than this often has been obtained. For a 

 two-passenger carriage, at the prices ordinarily 

 prevailing in American cities, the cost per mile is 

 one cent, or slightly more. This type of carriage is 

 rapidly coming into vogue. The advantages of 

 the electric carriage are cleanliness, flexibility, ease 

 and completeness of control, simplicity, freedom 

 from noise, odor, and vibration, and, compared with 

 the horse, economy of operation within the limits 

 of reasonable deterioration. Its disadvantages arc 

 the weight of the battery and its limited mileage. 



