NOTES.

Press, Volume LXIII, Issue 19155, 11 November 1927, Page 5

NOTES.

"Roadster" invites articles and ; paragraphs of interest to motorists for i this page.

According to Mr H. Macintosh, Clii'-f Traffic Inspector, there has been less trouble occasioned by motorists during, die present Carnival period than ever before. He attributes this to the iact ihat he has'a larger staff of inspectors ihan previously, enabling him to keep better control of the traffic, and also because the motorists themselves apappear to be more- attentive than is usually the case to the by-laws.

In reply to a request regarding methods of testing speedometers, the Wellington Automobile Association at its last meeting received a letter from an expert, which stated that it was very difficult to arrange any typo ot testing equipment suitable lor all makes of speedometers. Each typo ut speedometer had a different standard speed. One make, at .3360 revolutions p.er minute recorded 60 miles an hour, while another at the same revolving speed, recorded over 180 m.p.h., because the latter read 60 miles at 1000 revolutions a minute. This was further complicated by the fact that several makers made different models running at different speeds adapted for different models of cars. This would involve different types of adaptors before the testing machine could test the different speedometers. A rough sketch of a suggested machine was attached to the expert's advice, providing for the adaptations necessary to test speedometers under various types of car connexions.

It is obviously absurd (remarks an English exchange) to preach safety first to pedestrians and at the same Time allow motorists lacking in necessary experience and qualification to venture upon the road. We hear much about the risks to which motorists are exposed by the folly of pedestrians, but not half enough about the greater risks to which they are exposed by the folly of incompetent drivers. "We .shall never gain adequate protection save by educating all concerned. What should be done with old, old, very old cars? They are dangerous on the road, because they have passed the limit of reasonable wear and tear, and they keep on turning up as "trade-ins'* which are somehow traded-but again to work a little more havoc on bank accounts and nerves. A group of dealers in California is seriously considering cutting,the loss on old "tradeins" and ending their careers in a large junk bonfire.

When a car is difficult to start, or when the engine appears to be firing unevenly, it is generally thought that a reliable test for the sparking plugs ia to place them on top of Hie cylinder block, depressing the starter button and noting if sparks appear at the plug points. It is well to remember, however, that this test shows onlv that the magneto is functioning, and* that at least some electrical energy is being delivered to the points. It does not in an-, way follow that because a weak spark will bridge a 6 m-m gap in air it will do so under compression. A leak may be present in the high tension cable, also, which will not affect the free spark in air, but when the •plug is subject to the compression in the engine cylinder the spark may take the easier path from the cable to earth.

A writer in one of the Sydney newspapers suggests a simple method of dealing effectively with what are termed "road hogs." The remedy, he says, lies not in the punishment of motorists who have little or no respect for other people's lives, but with the maufacturers of motor-cars. Cars, it is suggested, should be geared in such a way that it would be impossible for drivers to annihilate space and also life itself. The contention is that, even in these days of hurry and bustle, there is no reason for speed beyond, say, 35 miles an hour, and that, beyond that speed, few men have effective control over their cars. As the matter, however, is one peculiarly for the legislatures of other countries, the suggestion that a law should be enacted, forcing manufacturers to cut down the speed of all motor-cars, is likely to fall on deaf ears.

It is not often realised by motorists the importance of keeping axle fittings dead tight. Many owners consider that because a taper and key are employed to fix the inner hub to the axle shaft the key is intended to take the whole of the drive. Actually, however, this is far from the case. The taper itself takes practically all the drive and the key is merely a safeguard chiefly against shock loads. On cars fitted with semi-floating axle shafts the importance of tightness for the inner hub upon the shaft canont be overemphasised, as any slackness here results in continual bending in the end of the shaft, which will eventually cause crystallisation, fatigue, and fracture.

The increasing interest in the development of roads which is being displaced in Argentina is reflected in the appropriation of 20,000,000 paper pesos (approximately £1.680,000) for roadwavs contained in. the Budget of that country.for 1027. This is a record appropriation for such work and indicates a steady increase since 1918, when 1,467.000 paper pesos were set aside for this purpose.

THE BATTERY.

QUESTION OF OVERCHARGING. The question whether overcharging does or does not injure a battery is one which closely concerns the ownerdriver, who often wants to know whether he should always keep the battery on charge whatever its condition. The question was recently dealt with by the chief engineer of a well-known battery manufacturing concern, who (Kiinted out that overcharging does harm in several ways. The lowering of the electrolyte level by excessive decomposition will, unless made good, uncover the upper portion of the plates and increase the current density on the covered portion of the plates, resulting in overheating and abnormal depreciation.

In certain batteries in which the plates are not protected by a complete diaphragm or separator particles of lead or lead sulphate carried up by the circulating electrolyte will form spongy lead on the upper edges or on projecting ledges and in time bridge across and short circuit the plates. These also suffer material damage, the active material of the negative plates, contracting and the grids of the positives becoming oxidised, and further more the active material of the positive plates suffers from mechanical and chemical effects. Overcharging, therefore, does cause increased depreciation.