MOTORING

Nelson Evening Mail, Volume LXVI, 19 August 1933, Page 4

MOTORING

ADJUSTMENT OF HEADLIGHTS AVOIDING DAZZLE A PROBLEM FOR MOTORISTS The problems associated with glaring hcadlights'and safe road illumination at night have for a long time perplexed traffic experts. Although many inventions have been developed and "marketed, the fact tremains that no anti-glare device has yet been universally adopted. The situation is made more difficult to-day because of faster speeds and the increasing use of bitumen for road surfacing. Even with powerful headlights tho illnnininatiou of a bitumen road, especially when it is wet, is often inadequate, and another risk is created by tho dazzling beams of light from oncoming cars, which arc far more troublesome to drivers than on a whitish concrete or gravel surface. Various expedients have been tried, such as dimming switches and tilting headlights, but as a rule traffic experts consider that such appliances arc more dangerous than useful, in that they make a call upon the attention of the driver and also, either by reason of lowering the intensity of the lights or causing beams to dip abruptly, impair the projection of the rays, so that driving vision is restricted. The practice of dimming is also condemned on the ground that it leads to confusion and risk, and recently the New South Wales Commissioner of Police issued a warning against it. To sum up the position, it might he said that the motorist is in the unfortunate position of having to make the best of a bad job and must at all times he careful not to “drive beyond the light”; that is to say, the speed at which he proceeds, having due regard to the nature of the road and the illumination from the headlamps of his car, should he such that he can halt the vehicle within the length of roadway which is amply lighted by the headlamps.

PRACTICAL ADVICE In an interview, Mr J. Fielder, an Australian engineer, offered much practical advice which should be valuable to many car owners. He states that more road accidents are brought about bv weak and badly-adjusted headlamps than by glare, and considers that one of the vital objections to many types of diffusing lenses and Masses is that they cut down the projection of the light to a dangerous degree. In New South Wales the regulations require that the lamps shall be so adjusted that the rays of light shall strike the ground not more than 180 feet in front of the motor vehicle; but Mr Fielder says that- if a literal interpretation is placed on the directions referred to, it is not feasible to set ordinary headlights in such a way as to assure an adequately long projection of the illumination. On the other hand, if the lamps are so adjusted that- the primary rays strike the roadway at the prescribed distance, the secondary rays without _ causing dangerous glare or confusing approaching drivers will light up the road ahead for a considerable distance, with the effect that the forward illumination is well diffused and the motorist is not, as it were, driving into a wall of blackness at a given distance in front of the car. The procedure advised for testing and regulating the headlamps is as follows: —• See first of all that the parabolic reflectors are glean, for a film of dust will, as has been ascertained by. laboratory tests, diminish the intensity of the light by 15 to 20 per cent. . The next step is to focus each bulb in its reflector by moans of the adjustment provided. To that end/ tlic beams should be directed against a wall or fence from a distance of about 20 feet, and each bulb moved backwards or forwards in its socket until a narrow circle of concentrated light is secured. It should he noted that the brightness of the lamps is sometimes affected by corrosion at tlic back of the lampholder, which, in the case of singlewire electrical systems, imposes a high resistance in the “earth” return circuit. After the bulbs have been focused as described the ear should he taken on to a level road and away from street lights, and a dark object set up at a height of about a foot and at a distance of 180 feet. The headlamps are then manipulated until the 1 main rays from each strike the object. It will be noticed that a dark line is thrown at the point where the main rays terminate and the secondary! rays arc projected at a higher level. When the correct elevation of the beams lias been secured, each lamp should be placed so that its light is projected in a straight line in front of ’ the car, and then given a slight inclination outwards. The effect of that 1 setting is to distribute the light over ■ a wider space, so that the full of tho road is lighted up and one can j detect in good time persons who aie ; crossing the highway and can better 1 discern tlic corners and turnings.

ELECTRICAL DEVICES STANDARDISING VOLTAGE IGNITION DEVELOPMENTS The time would definitely seem to have passed for changes of a really radical character to be made in the electrical equipment of the car, though tliere are many minor points that merit discussion.

One change, writes an English motorist, seems to bo overdue—namely, the standardisation of voltage as between British makers and their overseas rival. British practice now seems to have settled down to the acceptance of 12 volts, while American makers favour (i volts. While there was no effective competition between the products of the various countries the matter was not of great importance; and, for good or ill, C volts is accepted in many markets as standard. The result is that certain British car manufacturers are adopting one system for home sales and another for overseas. The arguments in favour of each of the two systems seem to be well balanced, and the electrical expert, when appealed to, will admit that one is as good as the other. Electrical firms in England have met the situation in the only possible way, by producing both kinds of equipment to suit customers’ tastes. Slops toward standardisation will no doubt bo taken before long. Ignition developments are few. Automatic advance of ignition appears to gain ground, though slowly, at tho expense of hand control. The magneto persists in England, but is still retreating before its powerful rival, the coil and battery form of ignition. Details of the coil, and especially of the distributor continued to be improved, but

the fundamental principles are the same. With regard to sparking plugs, the type which requires only a small tapped hole seems likely to oust the oldei pattern, in the interests of combustion chamber design and bettei local coolTlic various ills that veic threatened, especially to cars of the spotting type’ from this development have been mercifully absent. Failure of ignition is much less frequent than formerly, and better staitintr in cold weather is the rule. This is partly attributable to the modern practice of enclosing the plugs hi a fumeconsuming head, or an ordinary cover plate, which protects the insulators from’the deposition of dew during cold or damp weather. The ignition also lias a better chance owing to the

modern development in carbuiettors, by which flooding at starting is unnecessary. The spark is therefore not required to pass through an over-rich mixture at starting. Cases or screens arc now available for fitting over spark

plugs used on cars to which wireless sets are fitted, with the object of quenching any interference with the reception o Alio "wireless set due to the sparking. Another aid to successful starting in cold weather is the improvement in batteries. Formerly the production of a long life battery for use under the severe conditions in which ymotor vehicles are used seemed to he a secret shared by few. Nowadays many batteries have been known to outlast the normal life of the car. The nickel-iron type, which was once thought superior to the lead type, lias made no apparent

progress. Starting, however, does provide the best instance of development in that a control lias been introduced to prevent stalling the engine. This is worked by the vacuum in the induction pipe, and automatically switches on the electric starter when tlic engine comes to rest

from any cause. It is connected with the ignition switch in such a way that when this is turned on the engine is automatically started, and will restart as often as necessary without further attention. There is a delay of about a second after the engine has ceased to fire before the starting switch is closed, to allow the engine to come to rest aiid thus avoid jamming the starter pinion.