THE SKID MENACE.

New Zealand Herald, Volume LXV, Issue 19892, 10 March 1928, Page 10 (Supplement)

THE SKID MENACE.

NEGLECTED TRAM TRACKS.

, The f wet ' weather and increased skid hazards call for caution on the concrete and bitumen roads. Matters are not improved by the neglected state of tram tracks on several suburban routes. In some cases the stone setts project dangerously, and the shock of striking some of them is sufficient to upset the steering unless anticipated. These irregularities on the road are not taken seriously in the summer, but winter nights, wet weather and poor visibility convert them into a menace. It might have been expected that everything would have been put in order during the fine weather. The rough edges of these tram track settings play havoc with the tyres if crossed at right angles at customary speeds. Even where the condition of the tradks does not annoy the*motorist, it calls, for careful handling of" a cycle or motorcycle. Unless something is done one may expect to hear of accidents directly attributable to these blots on otherwise firstclass roads. THE TVS SURVIVE. The automobile has been responsible for the development of a sturdier and incidentally a smarter race of roosters and chickens, according to Richard C. Haldeman, president of the Pennsylvania Motor Federation. Haldeman asserts that the large number of chickens killed on the roads duiing the early days of the automobile ago weeded out "mentally unfit roosters and hens.". __ LUMINOUS TRAFFIC DOMES. Luminous buttons are being installed on 15 of the traffic domes on city intersections. This is the result of the appreciation which motorists have expressed for the several domes which were fitted for test purposes some time ago. With good headlights the effect is certainly satisfactory and tfye danger of running over the domes and finishing up in a skid should be greatly reduced. The cost of fitting these danger signs to domes is £1 17s 6d each. The city traffic department has chosen orange lenses for the installations authorised. A VARIABLE GEAR. A novel infinitely variable gear with many notable features which has recently appeared is the invention of Mr. F. Ljungstrom, of Stockholm, an engineer whose name is well known in connection with turbines and other engineering works in Sweden. „ , , The gear is entirely controlled by one pedal, thus reducing the driving of a car to the last degree of simplicity. The effect in driving a car fitted witli this gear is that the engine can be started in the usual manner, but no motion will be imparted to the • car until the pedal is operated. The brakes are normally in the " on" position, and a slight depression of the single pedal takes them off and permits free-wheeling. A further depression of, the pedal causes the car to begin to move slowly and, as it-is depressed to its utmost, not only does the engine develop its full power but, in addition, the transmission provides exactly the right ratio that will permit the. engine to retain its full output. It automatically adjusts the ratio between the engine and the road wheels according to the resistance due to inertia or gradient. By this means the driver has only to look after his engine speed, and the ratio between engine and road wheels will automatically look after itself. ' . „ This gear differs in important details from the infinitely variable gear employed on the Constantinesco car which was re- j cently put into production. POWER LOSSES. Wind resistance encountered by a car goes up by about the.cube of the speed. Therefore, the resistance increases much faster than does the speed of the car, and consequently the higher the rate of speed the greater the percentage of engine power which is lost. It has been estimated with one particular make of car that, petrol . mileage drops by abput 3 in.p.g. for every increase of 10 m.p.h. above a certain 'figure. For example, if the owner was getting 19 m.p.g. at 25 m.p.h., the consumption would be 16 m.p.g. at 35, and 13 m.p.g. at 45. Once a car, is into its stride only a small portion of its power is required to keep it moving at a constant speed on the level. A moderate weight car requires about 6 h.p. for its propulsion at 30 m.p.h. on the level. Immediately a hill is encountered, or if it is desired to accelerate rapidly, a full throttle opening may result in the delivery of 20 or 30 h.p. It is interesting to observe that cars which niav sweep along at 35 m.p.h. on the level with the expenditure of only 10 h.p. may be fitted with engines rated as high as 35 h.p.. and developing up to 90 brake h.p. It seems a waste to carry this energy in reserve,, but there is no alternative with the orthodor gearbox if one wants power for hills and emergencies. The infinitelv variable gearbox is an atterrmt to abolish hitth-powernd engines. With an infinitely variable cear there is little loss in the transmission of power, and a 1000 c.c. motor-cycle engine can be made fo nropel a sevenseater car with remarkable economy.