X, DEMON.

Otago Witness, Issue 3969, 8 April 1930, Page 67

X, DEMON.

“ It may not be generally known among yiotorists that if a car’s brakes are put on suddenly and then the accelerator is used, the car can be swerved in any direction the steering wheel is turned,” said a witness in a dangerous driving case in the Wellington Police Court the other day. He stated that he adopted this method of avoiding running over a woman who was knocked down by his car. It was a valuable precautionary measure in such emergencies. “ It is not sufficient for any one party involved in an accident merely to inquire if the second party has been injured,” said Mr E. D. Mosley, S.M., in the Christchurch Magistrate’s Court the other morning. He added that some definite steps had to be taken by the parties to ascertain if one or the other had been hurt. This statement was made during the hearing of a case in which a man was charged with failure to report an accident. He knocked down a cyclist, but contented himself with asking the latter if he had been injured. In an effort to quell the nuisance caused by noisy motor cycles, city traffic officers in Auckland have been instructed to report all cases that come under their notice. The chief traffic inspector, Mr G. R. Hogan, recently requested motor cycle clubs to advise their members to have efficient silencers attached to their machines.. Many complaints have been made about the thoughtlessness of motor cyclists in travelling along suburban streets at night with open exhausts, and the decision to prosecute all detected offenders is made in the hope that the annoyance will be greatly minimised. A dog sat in the dicky seat of a motor ear which was coming into town from Island Bay (says the Dominion). His pwner had carefully chained him there. Something on the road attracted him, pnd out he leaped. The car was travelling at a good pace, and the pet was immediately pulled off his feet and dragged in the wake of the vehicle. Another motorist following Seeing what had happened sounded his horn to attract the attention of the owner of the dog. Unfortunately the meaning of the signal was piistaken. To the driver of the leading car the sound of the horn came as a challenge. It was taken as an intimation that the one behind wanted to be in front; and to his mind it was a challenge. Down went the accelerator and up went the speed, until the unlucky animal was dragged to death.

TOURIST TROPHY RACE. One of the best known Auckland motor cyclists, Mr Len. Coulthard, has left for England to take part in the Tourist Trophy race early in June. Mr Coulthard, who has ridden successfully on grass tracks throughout the North Island for some years, is also a clever performer on the cinders, and provided that he is. able to obtain some intensive practice over the difficult T.T. course, he should acquit himself well against all comers. He is travelling at his own expense, Percy Coleman having been chosen as the official New Zealand representative. Mr Coulthard may enter a Velocette machine privately for the Junior and Senior events, or possibly be included in the official .Velocette team.

SLIPPING CLUTCHES. Slipping clutches invariably cause unnecessary wear practically to all moving parts of a chassis. It is frequently found that grease or oil works its way from the spigot shaft bearing down on to the clutch cone, eventually causing the clutch to slip. This trouble is usually experienced when a spigot shaft bearing has become worn and the lubricant naturally finds its way on to the cone. In this ease a renewal of bearing cures the trouble, but there is, of course, a certain amount of grease or oil on the cone, which should be wirebrushed or burnt off.

■ With Ferodo-lined clutches the usual methpd adopted is to pour a little petrol on the lining and light it, when all greasy substances will be burnt off. After this a few rubs with a wire brush will greatly improve the surface of the clutch lining. If there is not sufficient time to dismantle the clutch, the application of a little fuller’s earth to the cone will assist the clutch to grip by absorbing any excess of oil.

WIDE CHOICE OF MACHINES. Over 300 different motor cycles ranging from 147 c.c. two-strokes, costing about £2O, to 1000 c.c. machines, priced up to £l7O, are obtainable in England to-day. Actually, motor cycles are cheaper to-day than pre-war. but in specification, design, and manufacture the modern machine js incomparably superior.

POSITION OF THE PETROL TANK.

Much attention has recently been drawn in England to the position of the petrol tanks on the majority of small cars, in front or -above the knees of their drivers and passengers and exactly in that part of the car that usually gets it worst in the event of a really bad head-on smash. For economy and convenience this situation for a tank cannot be equalled, as well as for performance, and it is only fair to mention that fatal accidents arising from this particular cause are not nearly as frequent as might be expected. But, when they do happen, they can be very serious indeed, for one’s clothes once saturated with petrol, are liable, to make even the shirt of Ness us a back number, while the consequences of a flaming tank inside a closed ear are almost too horrible to contemplate. The proper place for all tanks is outside the car and behind it. But when the uninflammable fuel that has been heard of lately comes

into ordinary usage, it will not matter in the least where we put it or what happens to it.

AFTER AN OVERHAUL.

Drivers are sometimes dissatisfied with the performance of their cars after an overhaul or decarbonising treatment. They do not get the same power or acceleration as before. The reason is that no engine will give its best until the rings of the pistons have settled to work closely on the cylinder walls, and the valves have become bedded down on their seats. Also many , engines give better power after there is a certain amount of carbon deposit on the walls and piston head. Let things settle down for about a couple of hundred miles, and then adjust the valve tappets to get close and uniform clearance. It will then usually be found that the original efficiency has been regained.

INTERESTING JUDGMENT. An interesting case to motorists was recently heard before the State Full Court in Victoria, in which an owner claimed from an insurance company £2OO under a policy of insurance on a sports model ear which in 1929 was destroyed or greatly damaged by fire when being prepared for a race.

The insurance company refused to pay on the ground that the’ owner in giving particulars for the policy had not stated that the car had competed in a reliability, petrol consumption test, or that he intended to use the car for speed competitions, and that at the time of the fire the car was being tuned up ” for a competition. In the first trial of the case the judge found that the company’s defence failed, and gave judgment for the amount claimed with costs. Then the company appealed. Concluding the hearing of the appeal, the Chief Justice in delivering judgment said the first ground relied upon by the company was that the owner applying for the policy had not disclosed that he intended to use the car for racing, and that this being a material fact the policy was void. The policy, however, seemed to show that the use of the car for racing or reliability trials w’as contemplated by both the owner and the company. The non-disclosure of the owner’s intention to use the ear for racing became immaterial. Another ground of the appeal was that the company should not be held liable if the car were used for any other purpose than business or pleasure. It had been urged on behalf of the company that preparing a car for a race did not come within the words business and pleasure. In his Honour’s opinion it was quite unnecessary for the owner to show that the car was definitely used for business or pleasure. These words were to be construed as meaning for the purposes of business or for any other purposes the owner might choose to use his car for; and in the opinion of the full court the racing of the car, as it was raced, fell within the meaning of the words business and pleasure, and the appeal was dismissed with costs.

SIX V. FOUR WHEELS. Major C. Court Treatt, whose name is always associated with the Cape to Cairo expedition a few years ago, has recently returned from the Sudan, where he has been making the film “ Stampede,” for British Instructional Films, Ltd. During the expedition Major Court Treatt relied entirely upon, a six-wheeler for the conveyance beyond the El Obeid railhead of kinematograph kit and boys, in addition to which three boats were carried. Although the maximum load, as laid down by the manufacturers of this particular vehicle, for cross-country work is 2 tons, the vehicle worked consistently with a load of 5 tons, and Major Court Treatt states that on every occasion when he gave a thought to the excessive load he blush-ad to the colour of the plate on the dashboard on which was a notice to the effect that overloading would invalidate the manufacturers’ guarantee. On occasions when travelling through the bush the springs were on the buffers. In view of his considerable previous experience in touring Africa, Major Court Treatt’s opinion of six-wheelers is of some consequence, as he is in a position to compare the performances of this with its four-wheeled prototype, or, as some Arabs said, a car with six, instead of only four, legs. The performance of the six-wheeler was such that at times it appeared to be almost uncanny. Fitted with tracks on the back wheels and using the doublereduction gears, no obstacle proved insurmountable. Rivers which had almost dried up and which had vertical banks “were negotiated after cutting away the banks to an angle of 45deg, and then leaving a rough earth surface. This, of course, would be impossible with a four-wheeler. In the swamps, too, the vehicle came through with mud up to the axles, and through it all remained sufficiently rigid to enable photography to proceed. Incidentally, moving shots required for the film can only be secured in a satisfactory manner when the camera is rigid and does not sway unduly with its base or stand. Acting against general advice of everybody in the district. Major Court Treatt set off for parts of the River Shaleika, which had never before been visited by a white man. On this part of the expedition trouble was encountered. Numerous holes, caused by elephants walking over the ground when wet, were during this drier season covered with grass, and therefore were invisible. Proceeding in normal manner one day one of the front wheels dropped suddenly into an elephant hole and everybody on board, except the driver, was thrown off. The accident pushed back the front axle and bent one of the dumb-irons. After dismantling,

the front axle was placed in the fork of. a large tree and, while cold, straightened by brute force. After resassembling the front, axle, the bent dumb-iron was chained to another firmly-rooted tree and, after loading the car with stone, mud, and any other ballast available, the member Ayas pulled into its original shape by reversing the car under its own power. On another occasion- the lack of a comprehensive stock of spares and tools caused a considerable delay. The car ran into the stump of a tree, and a hole in the radiator was the result. Cutting the hole square and closing the ragged edges of the honeycomb walls with pliers, the job was complete except for soldering, which had to be accomplished with the aid of an ordinary charcoal fire. Some five days were occupied in executing this repair, but it is satisfactory to note that beyond fitting a new front spring, no replacements of any description were required or used during the expedition, and, although the total mileage amounted to over 10.000, the engine was decarbonised and the valves ground only once.

A PRECIOUS MISPRINT. By such a simple thing as a compositor’s error, almost a daily happening in the realm of journalism, The Times has presented posterity with a brand new word. In a sub-leader, not long ago, the writer was discussing the position held by the Greeks before rapid wheeled transport or “ hogging ” were ever thought of, and Ire referred to the ancicent Athenians looking down on a world filled with barbarians. On the proof, by that accidental slip which sometimes adds a touch of genius to the commonplace, the last word read “ carbarmans.”

“ It seemed a shame,” the writer in The Times explained, “to alter the accidental slip. But the gift was only delayed. We offer it now—carbarian —as the perfect name for those who drive to the public daoger, those -who lack the manners of the road, and defy, the tradition of th'e road—the young carbarians, all at play in their motor coaches, the innumerable divisions of the class inadequately named roadhog. Such a misprint is hard to parallel, for few of these mistakes are creative. Thus appears the new word with which Printing House square enriches the language.” _

MANUFACTURE OF PLUGS. Those who drove automobiles a few years ago will recall vividly among other troubles the inconvenience caused by cracked spark plugs. To-day, we have practically forgotten about spark plugs, as they have ceased to be a source of trouble,

and one hardly ever hears of a cracked porcelain any more. Explaining why spark plugs do not crack, and the way this improvement was brought about, was recently described by a member of the United States Geological Survey. In June, 1926, in the course of field work in California, a geologist saw an outcrop of rock that had been taken by one prospector for silver ore, and by another for phosphate. It evidently was neither, and so far as its appearance indicated was merely one of the host of rocks that compose the bulk of the earth’s crust. However, the geologists, recognising the mass to be of an unusual character stole time enough from the otherwise economic work assigned to him to gather specimens and to ascertain the facts of its occurrence. Later, an examination of his collection showed that the rock was largely composed of a mineral called andalusite. At that time andalusite was not known to have any economic:value. But, because of its scientific interest, a description of the occurrence was' published in a scientific paper.

Before that time the silicate materials had been one of the many subjects of investigation by the geophysical laboratory, which had among other things determined what to the layman might appear to be a bit of perfectly useless information—namely, the amount of swelling and shrinking shown by andalusite and other minerals when they were heated and cooled: or, in scientific terms, their coefficients of expansion. The geologic paper and the results worked out by the physicists fell into the hands of engineers looking for substances with which to make spark-plug porcelains that would not crack, and the andalusite was the answer. The geologist’s research had found the deposit, and the physicist’s research had shown its suitability for the purpose sought. Again in the course of field work, this time in another part of the country, the same geologist discovered another scientifically interesting occurrence, a mass of the mineral dumortierite, which, in the course of events, he described and for which the physical properties had been made known as before, with the result that the spark-plug makers were directed to a deposit even more valuable for their purnose than the andalusite.

To-day, as an indirect result of purely scientific, uneconomic investigations, we drive our automobiles with never a fear of a “ missing ” plug.

WEIGHT OF THE CHASSIS. An authority on automobile design, without bias towards any make of car or feature of design, asserted recently that in the design of the average car of to-day 15 per cent, of the chassis weight of the car as a whole could be cut out without decreasing its efficiency or length of life. This was stated to be a conservative estimate, and to take account of dimensions alone. It was quite apart, that is to say. from the use of lighter materials, such as the substitution of aluminium alloys for steel and iron at some points where these latter are now current. Without suggesting what proportion of the cost of the average car is due to material cost and labour charges, respectively, this authority goes on to say that a car costing £lOO for material would cost £2O less if the 20 per cent, reduction in weight were effected, and that this economy in cost could be made up by the smaller weight of material to be paid for in a “ raw ” state, the smaller amount to be removed from metal parts by machining processes, and the lower price that would have to be paid for the lighter parts, that were purchased finished and ready for fitting to the chassis or body work. Undoubtedly the performance of a car depends on one thing only, and that, is its. power to weight ratio. A 30 h.p. car weighing 30cwt. will, for example, perform much better than a car of similar power which weighs two tons. But in order to get the highest preformance it is not sufficient to put an enormously powerful engine into a flimsy chassis. Such a method of construction, although giving sensational results, invariably ends by trouble being experienced with the chassis and transmission. The designer who would build a very light car has other things besides technical difficulties to overcome. One of the chief obstacles is public opinion, for the main body of motorists has very firm ideas of what is done and what is not done in automobile construction. It has often been shown that much weight could be saved by scrapping dumbirons back and front, and using quarter-elliptic springs. Yet, to-day it is a very courageous firm which will, in defiance of public opinion, use this system 'of suspension, which is perfectly sound technically, just as it shows a fine, but seldom commercially successful, spirit of independence to put the gearbox, or some other main component, in an unorthodox position.

Consequently, manufacturers ; are going deeply into matters of metallurgy, seeking new metals which will give them the required strength. Sooner or later car manufacturers in general are likely to take to aluminium cylinder blocks, with steel linings, and upper halves of the crankcase also of aluminium. At the moment cast iron is preferred because it is not onlv considerably' cheaper, but bulk for bulk it is stiffer and better suited to counter vibration. For the same reason, although aluminium gearboxes have long been the rule, some motor manufacturers use iron or steel in order to ensure silence and rigidity.

The heaviest part of a car is the engine —which probably weighs most —the axles and springs are also very heavy components; but we are no doubt approaching the time when by using some suitable alloy the weight of the front axle can be reduced, and so far as the rear axle housing is concerned, this is already in some cases made of aluminium. The chassis frame itself is by no means as heavy as one might at first sight imagine, but the springs are unduly heavy. Anyone who could devise some sort of duralium springs would effect a great saving in weight. Clever engineers in Great Britain are now at work on this problem, and it is not impossible that in a few years’ time with new methods of construction a strong, light, and beautifully streamlined car can be produced.

PROGRESS IN DESIGN. Will the body designer become eventually the designer of the car as a whole? This may have been asked before, but current hnnpenings bring it more forcibly to attention. Progress in d A si:rn for many years has followed the line of

improving the conception of a chassis on which a body is mounted. Gradually, however, this marriage of two distinct and complementary units has been clothed more and more completely with fenders, aprons, and shields, all tending to blend the separate identities into an indivisible unit. Thus the body designer has taken over the function which the automobile builder created, but never cared to carry to fulfilment. So to-day the body builder very largely controls the product as far as carriage work is concerned, but has nothing to say about the chassis. This he finds somewhat cramping to his style. He might go' further and faster, he feels, were he given a freer hand in specifying, controlling dimensions, and locating certain units, instead of merely shrouding the mechanical assembly which engineers have contrived. The point is that many things about chassis designs have become traditional and remain unchanged because of inertia rather than engineering necessity. There is no particular reason why a good many alterations might not be made, provided good reasons were to develop. Reasons for such alterations as these are less likely to arise out of engineering necessity, however, as from the struggle of the body builder to produce a better looking more comfortable and. generally more satisfactory car. So the question is how far the body designer will be permitted to go in realising those of his ideas which involve engineering changes, and how far he would go if left entirely to himself.