Tire Tracks
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By GillcraftThe Tracks of Bicycles, Motor-Cars, and Other VehiclesIn the latter part of December 1921 there appeared in the Morning Post several advertisements from cooks, desiring situations. A chauffeur named Allaway, in private service in Bournemouth, answered three of these by telegram, saying that the advertiser would be met at the Central Station. Two of the women ignored the offer, but the third arrived after dark. She was met by Allaway, who drove her down the main road to a lonely road near Ilford Bridge and there murdered her. Afterwards he drove back along a newly-constructed road to a quarter where traffic was heavy - Fisherman's Walk. The news of the murder appeared in the evening papers the day after the occurrence. That afternoon, before the evening editions appeared, Allaway drove the wife of his employer to pay a call in Branksome. While she was in the house, Allaway backed the car, in the dark, into some rough ground to turn it. He took the opportunity to throw away the deceased's attaché case, where it remained hidden in the bushes for a week. Meanwhile Allaway had been arrested for stealing his employer's check-book and forging checks. The handwriting on the checks resembled in some respects the handwriting on the telegraph forms, but in the checks the handwriting was obviously disguised. A search of Allaway's rooms, however, revealed further writing which was stated by an expert to be exactly similar to that on the telegraph forms. Immediately after the discovery of the murder, the marks of Dunlop Magnum tires were found on the soft side of the gravel road. The marks were deep, indicating the passage of a heavy car. These marks were tracked for about two miles along a circuitous route to, and along, the newly-constructed road. Two Types of Dunlop Cord Balloon TYPES OF MOTOR TIRE TREADS The subsequent discovery of the attaché-case, and the marks of similar tires, at first gave the impression that after the murder the culprit had driven at once to Branksome. No finger-marks were traceable on the attaché-case, as it had lain out in the open for a week. But it was found that Allaway had bought an evening paper on his return from Branksome, and was seen next morning changing the tires on the car, and substituting Michelins. The combination of circumstantial evidence led to the conviction of Allaway: Recognition at the station; the handwriting on the telegrams, checks and other papers; the discovery of the attaché-case; the marks of the tires both at the scene of the crime and where the attaché-case was discovered; the changing of the tires after the news of the murder had been published. [tt127] The tracking and tracing of the tires contributed very largely to the success of the investigation. The actual tracking was a very good piece of work, for it is not easy to track a car along a newly-made road, some time after it has passed. As I have already remarked, it is a useful practice to try to remember the number and make of the cars that pass. If a Scout is in the habit of doing so, he may often be able to give valuable information to the police when they are trying to trace a stolen or wanted car. If an accident has happened, and the driver of the car responsible has been able to get away before you could read his number, there is still a good clue to try and follow, and that is the track made by the tires. You should remember, too, that the pattern that the tires have made in the mud or dust is as important, if not more so, than just the rut or mark of the line of flight. It is difficult for two different cars to leave exactly the same track. The different makes of tires all have different patterns in their tread. Apart from this, it is possible to distinguish the mark of an old Dunlop, say, from that of a new one, to note cuts or patches on the tread, so that you can recognize the same track if you come across it again elsewhere. Again, a car may have one pattern of tire on one wheel, another pattern on another, and so on. One tire may be old, one partly worn, another new. The front wheels may wobble, or one wheel only may be out of alignment. There is, you can easily see, a lot to be learnt about, and from, the tracks of tires on the ground. If you are setting out to follow the track of a car, the first thing you want to decide is the direction in which the car is going. Unless it is proceeding backwards, and that you should easily be able to tell by the uncertain line, the marks of the back tires will cover or cross the marks made by the front tires. If the car is known, and the patterns of the tires known, this may help you in some cases where the pattern of the tread is at an angle to the line of running, as in the case of the Dunlop Cord Balloon illustrated. But you will have to remember that the tire can sometimes be put on two ways, and that even when a tire is on, a wheel is sometimes reversed. Your clues to direction, therefore, are usually better given by stones and dust and mud. The tendency is for the wheel of a car to push a small stone it runs over slightly forward, and, after pushing over it, to kick it back. If the car goes over a bump, the tires will momentarily broaden out on the far side of the bump on account of the impact. Dust and mud and water will be thrown outwards and slightly backwards, although in going through a puddle the wheel will push the water forward, and violently so if the car is going fast. [tt129] Naturally it is very difficult to follow a car track on a smooth, hard-surfaced road, but not impossible, as the Bournemouth Police proved. If the road is damp and there is a tendency in the car to side-slip, the side-slip will show in the direction in which the car is proceeding. There is scope for considerable investigation in the art of side-slipping, but it is a dangerous practice. I have, however, known it purposely done by some men who have had to take their cars into dangerous quarters and who have learnt to side-slip so that they could turn about quicker! A great deal of what I have said in regard to the patterns on the tires of motor-cars applies equally to the tires of bicycles. There is as much variety of design, and as much chance of being able to identify the track of one machine from the track of another. The direction in which the cycle is going is slightly easier to tell. As the rider has only two wheels on which to go, he has to add the complication of balance to his steering. If the rider loses his balance, he has to twist the front wheel suddenly in order to recover it, and then gradually bring the front wheel back to the straight. [tt131] DUNLOP CORD BALLOON TIRE AND TRACK MADE BY IT This will be depicted on the ground; the track of the front wheel will suddenly and abruptly diverge from that of the back wheel, which usually covers it, and will gradually converge to the central line, leaving a kind of arrow mark made by the tracks of the two wheels pointing in the direction in which the bicycle is going. If the rider is going fairly fast, dust and small stones will be thrown out in a slightly forward direction. But it is when the track comes to a hill that it is comparatively easy to see in which direction the rider has gone. Uphill he will be laboring on his pedals, his balance will be uncertain and the tracks of the two wheels will not show as a single track but will wobble about. If he is going downhill, the track will be straight, the back tire covering the front. It is, of course, a matter of balance, and it is just the same when you are on a bicycle as when you are on your feet. The faster you go the easier it is to maintain your balance, and so, in each case, your track will have a more central line and run straighter. The direction of carts and other vehicles which are not self-propelled can be learnt from the tracks of the animal pulling the cart, or of the Scouts pulling the trek-cart, if these are visible. Otherwise, by walking slowly along the track and looking carefully, you may be able to see a stone, a twig, a piece of straw or some other small, loose object displaced by the wheel. These things are nearly always pushed forward to a noticeable extent. A bump will cause the wheel to leave the same kind of clue as that left by a motor-car. On a damp country road, too, the wheel drags up the earth behind it and forms serrations the shape of which will indicate the direction in which the wheel was moving. Just as a heavy motor-car will naturally make a heavier impression on the ground, so will a heavier cart leave a deeper rut. Its contents may possibly be discovered, if a sharp look-out is kept on the ground for anything that may have dropped from the cart, and on the trees and hedges for anything that may have been caught up as the cart passed. When hay is being led, you will have noticed how wisps of it are caught up on the hedges, so that a very clear trail is left from the field to the rick. It is also possible to identify the nature of the particular vehicle that left the track - two- wheeled farm cart, four-wheeled timber wagon, and so on - by the distance apart between the ruts made by the wheels, and by the breadth of each wheel, which differ a good deal according to the particular type of vehicle. Possibly the most favorable opportunity for seeing vehicle tracks in a town is after a very slight shower of rain when the roadways are only wet in patches some minutes after the shower has passed. But then one has to remember that the roadway is dangerous. Let the tracks be noticed from the pavement, discourage Scouts from rushing into the roadway to look at them, or at the number of a passing car. Not so long ago a rumor arose in London and other large cities that a prize was to be offered to the school child who could jot down the largest number of index numbers of cars that he had noticed. This led to children darting into the street at unexpected moments in order to see more clearly the number of a passing car, with a consequent increase in accidents. The Scout should be able to see the numbers from the pavement and should have no need of getting into the roadway. If this point has been accepted as a matter of pride, then competition in the Troop to collect numbers can be held. Otherwise such competitions should be taboo. During the annual camp, however, there are usually opportunities for studying the tracks of carts, and other country vehicles in the vicinity of the farm, just as there are opportunities for studying the tracks of farmyard animals. |