COUNTRY TOURING.

Greymouth Evening Star, 31 December 1937, Page 11

COUNTRY TOURING.

STILL NEED FOR CARE ! Many drivers are inclined to relax their viligance when touring in the country. Motorists should realise that country highways are not always as innocuous as they appear. AVhen a car is travelling fairly fast, the uneven surface of the road tends Ito develop in the car a more or less I even rise and fall in the springs, and the wheels dance about on the uneven surface so that their adhesion on the . i'oad surface is almost at a minimum. Consequently should some unexpected emergency arise and the brakes be ap- . plied hard, the wheels, bouncing in the 'air, will tend to lock, which will make them bounce even more when they .touch the bumpy surface and the car ■will skid and slide forward with al■most unchecked momentum. In these I circumstances, the high crown of a i narrow road will tend to make the car slide off to the side.

On the other hand, if the driver de'cides to travel slowly, the car will be 1 almost as uncomfortable, because the springs will have time to flex to a ' greater degree in each direction between bumps, so that it becomes very ■difficult to know how best to deal with the conditions. | An old quotation may be altered to: | “He travels safest who travels alone” as a guide to drivers of little experi'ence endeavouring to maintain a fair I speed on country roads, and particu'larly on that, type of road described. 11l is remarkable how frequently, on Jan otherwise almost deserted highway, •one overtakes a. convoy of four or five cars, a few feet only between each one. ! Should something happen to the lead- ' er. a multiple collision is almost un-

avoidable, and this occurs far more frequently than many drivers realise. When such a convoy is sighted, it is wise either to overtake it or drop back, and unwise to join it. The driver who does, finds that he must watch the car ahead most carefully in order to maintain station and to be ever ready with the brake in case the leader decides to stop, slow down, or finds himself in such a position that he must pull up suddenly. The strain ot driving in these conditions is far greater than in travelling twice as fast with a clear road ahead. A good principle to follow is to keep as far away from other motorists as possible, and to pay careful attention to the road surface. Be particularly careful when the surface is uneven enough to keep the -wheels dancing. Wheel adhesion then is poor, and a car whose road-holding qualities are not very good will probably sway gently from side to side. Passing in these conditions is dangerous, Avhile what racing drivers call the “cut-off” point before a. corner —that is, the point where the right foot is moved from the throttle to the brake —should be chosen a considerable distance before the bend, and the brakes applied very gently so that there will be no risk of inducing a wild, dry skid. Fairly fast travelling on a good road is safe provided there is no other traffic and that the driver remembers this most important thing, that a car’s stopping distance increases as the ’square of the speed, and not in proportion to it, so that Avhen a corner or another car appears ahead, the brakes need not be applied while there is available at least four or five times the distance sufficient at the more sedate pace maintained in a town.

BATTERY FACTS. USE OF THE STARTER. Some motorists still avoid as far as they can, using th‘e starting motor for fear of shortening the life of the battery. There is no need for any uneasiness in this regard. The chief engineer of one of the biggest of the battery firms says that the modern battery will take no harm from discharges for short periods at any current within the carrying capacity of the conductors. Heavy starting currents do not promptly exhaust the battery, because as soon as the current is cut off, the battery voltage shoots up practically •to its former value; this can be repeated over and over again with the same results and without any recharging. Heavy- discharges do not buckle the plates. High discharge rates do not cause the positives to shed their active material. The lower the rate of discharge the greater the capacity obtainable; the yield from an aggregate of a number of short discharges at a specified rate is greater than that obtained on a continuous discharge at that rate. This fact will be appreciated by calling to mind what happens if the engine refuses to fire when the starter motor is first used. Switch off and then start again; the momentary pause allowed enables the battery voltage to recuperate. and the initial power on the next kick is thereby enhanced. Although the momentary discharge when the starter motor is used is high, the actual drain on the battery represents only a small percentage of its capacity. If an early morning start occupies three seconds’ use of the starter motor with a discharge rate of 200 amperes, the actual consumption amounts to one-sixth of an amperehour. Assuming that a dynamo gives a charge rate of 10 amps, and is working more or less at capacity, the amount of current used by the starter motor would be replaced when the dynamo has been charging for just over one minute. The buckling of plates is usually due to unequal expansion, which is not an effect of a high rate of discharge. It results as a rule from irregularities in I charging, or from an internal short circuit set up through faulty separators oi’ other causes. 'Phe active plate is usually shed as the result of a high temperature andi too much charging. The negative material will be shed if the electrolyte is I too dense. I