Horseless vehicles with explosive motors
Almost as soon as the gas engine was successfully reduced to its present simplicity and reliable action, inventors began to apply it to road wagon propulsion. Lenoir, in France, patented the first explosive motor vehicle in i860. Benz, in Germany, was one of the first to produce a successful motor wagon, which was publicly exhibited in Munich, Germany, in 1891.
Daimler, also in Germany, followed closely in the early years of the decade with improvements in explosive motors for marine and road propulsion. The new power idea spread rapidly in France and England and, with the electric motor, now forms the three principal systems of road motive power so largely in use in all Europe and the United States.
A host of experimenters in France, among whom may be named Serpollet, Peugot, Panhard, Lavassor, Kreiger, De Dion and Bouton, have contributed largely in perfecting the mechanism of the automobile and thereby giving it a distinctive reputation, upon which American inventors have widened its mechanical and economical adapta ion for vehicle construction and motive power.
'The Duryeas took up the experimental line in automobile motors in the United States, in 1886, and after five years of personal effort produced their first motor vehicle in 1891. Others fell into the same line of experimental construction, so, that the beginning of the twentieth century has found the motor power greatly perfected in all its parts. The introduction of solid and pneumatic tires has made a great advance in the comfort of riding and has contributed largely to the machine economy by the saving in wear and tear, from the excessive jar and vibratio' caused by the use of iron shod wheels.
The past decade, therefore, compasses the history of this branch of automobile work. The Benz wagon of its early date was not essentially different from its followers; being operated by a single four cycle cylinder, running at a high speed, reduced by belts to a counter shaft and by chain and sprocket wheels to the wagon axle. Since then the prime moving units have been duplicated in the explosive motor vehicle, and even three or four cylinders have come into use with most satisfactory results. Five cylinders give an almost constant impulse to the shaft and keep the motor in uniform motion, making it possible to dispense with the fly wheel, or to make it so light that its weight will scarcely effect the total weight of the running gear. Although the gasoline engine by its simplicity of construction and freedom from watchful care, as with steam, is better adapted for road wagon service, yet it has its faults of design to meet all requirements. In its present form it does not reverse and hence the necessity of somewhat complicated machinery for making its operation complete. With single cylinder motors, a high speed is necessary that the fly wheel may equalize the motion from a four or two cycle impulse. In spite of the few difficulties and inconveniences in operating a gasoline road wagon, it has as yet, but one real competitor for all - round service and for country touring.
Ignition for gasoline motors.
The hot tube for ignition is not in general use, although it has done well with small platinum tubes in English and German motor vehicles and motor bicycles. The constancy of the heating jet seems to be quite as complex to guard from shifting air currents and to ensure a continual generation and flow of gasoline vapor for the burner as is the electric ignition system, which appears to be generally adopted in the later European and American motor vehicles.
For a more special study of each system of ignition a reference to my work on " Gas, Gasoline and Oil Engines " is recommended, which also treats of the explosive technics of gasoline, vapor and air mixtures, and the management of explosive motors, with the theoretical considerations and formulas. Two kinds of sparking devices are in use. The separated electrodes, which require a jump spark from a single induction coil of the RhumkorfT type from a break device on the outside of the cylinder, and the single wire induction accumulator coil, with a wiping spark by break contact within the cylinder. Opinion is divided as to the merits of each method and their details of operation.
The secondary or jump spark, however, is not by any means so easy to handle. The insulation must be far more perfect, and even then in damp weather the spark will sometimes run along the surface of the external parts and thus miss the required "jump " in the explosion chamber. The points in the cylinder between which the spark should occur will become either at their tips or their bases covered with carbon deposit, which, acting as a conductor, again destroys the spark. Most of the various Rhumkorff coils, moreover, require a "vibrator" in the primary current, which is liable to get out of order. These troubles, bad enough with one cylinder, become worse when two are in use, and the commutation becomes more complicated in consequence. This form of coil, as a rule, requires a battery and does not work so well with a self-induction dynamo, so that for automatic use both battery and dynamo may have to be used, a dry battery for starting and a dynamo generator for a continual current.
With the single wire or sparking coil with current from a live battery or permanent field generator, or other generator giving a nearly constant current that is broken by a wipe or contact sparking device within the cylinder, there are also troubles, resulting in mis-fires. The wiper or hammer must be actuated by snap devices on the outside of the cylinder and may be well regulated as to time and varied in its movement to delay ignition for motor speed change. Its troubles arise from the same carbon deposit that effects the electrodes with short circuit, and the wipers wear quite fast. A hammer contact is good, but has its noisy troubles. The current for properly firing the charge should have an electro-motive force of at least ten volts; a weaker current will fire the mixture when all parts are clean, but much of the mysterious and unseen failures may be attributed to a weak current. The most suitable current gives a white or bluish-white spark, the red spark even, if large, is not reliable, whether a jump spark or a break c mtact. This essential feature should have means for easy observation in every electrically ignited motor, and should be the first to be examined when the motor stops from unknown cause.
The amount of compression effects to a considerable degree the certainty of firing from the electric spark. The heat generated by compression, increases with the pressure, so that a spark that fails to ignite at i5 or 20 pounds compres sion will readily ignite at from 50 to 60 pounds compression.