| Weight drawn. | ||||
|---|---|---|---|---|
| Level | macadamised road | 27 | cwt. | |
| „ | granite pavement | 30 | ·5 | „ |
| „ | wood pave„ | 54 | ·75 | „ |
And Lieut. Crompton has given the resistance of wheels in lbs. per ton on different surfaces as follows:—
| Very good pavement | 35 | lbs. |
| Good macadam | 60 | „ |
| Ordinary ditto | 90 | „ |
| Newly-laid gravel | 200 | „ |
| Soft grass land | 300 | „ |
| Newly-laid metal | 440 | „ |
Here “newly-laid metal” comes out very badly, and points to the necessity of rolling, of which I shall speak in a [future chapter].
Whilst on the question of wheel resistance, it may be well to note that the small front wheels of a waggon cause considerably more harm to a macadamised road than the larger hind wheels. In the smaller diameter any loose stone or obstruction is pushed along in front for a considerable distance, often tearing up the surface of the road, whereas in the other case the stone is forced into its place or crushed as under a roller.
On the question of “safety” to traffic, Mr. Haywood, the eminent Surveyor of the City of London, has caused several most complete observations to be made from time to time, the results of such observations being detailed by him in various reports. Amongst other useful information compiled by him, he has ascertained that a horse will travel 446 miles upon a roadway paved with blocks of wood without a fall, 191 miles upon asphalte, and 132 miles upon granite setts. I cannot do better than give verbatim his remarks upon this point:—
“Slight rain makes both asphalte and wood more slippery than they are at other times. On asphalte the slipperiness begins almost immediately the rain commences, wood requires more rain before its worst condition ensues. The slipperiness lasts longer upon wood, on account of its absorbent nature, than it does upon the asphalte; when dry weather comes after the rain, when asphalte is in its most slippery state, and the horses fall on it very suddenly, on wood their efforts to save themselves are more effectual; wood also is frequently in that peculiar condition of surface in which horses slip or glide along it without falling. A small quantity of dirt upon asphalte makes it very slippery, wood requires a large quantity. Slipperiness can be temporarily cured on both pavements; on the asphalte by sprinkling it with sand, on the wood by sprinkling it with gravel. The result in both cases is dirt. The sand thrown on asphalte helps to wear it out, the gravel thrown on wood tends to preserve it. When a horse falls on asphalte it has difficulty in getting up; on wood it rises more readily.”[11]
In streets crowded with traffic, the constant stopping and starting, especially on any surface that is slippery, is very trying to horses. Attention has lately been directed to this point with a view to the storage of some power in a vehicle, either by the compression of a spring in stopping or by some other mechanical means, in order that in starting the driver may at will liberate this power so as to assist the horse in overcoming the inertia of his load. These trials, however, have not at present met with much success.
Before closing this chapter on traffic, it will be well to point out that nearly all vehicles travelling rapidly can pass each other safely if allowed a clear space of eight feet; hence all roadways should, if possible, be made of a width between the kerbs of some multiple of eight: a convenient width for the footpaths, so far as foot-passenger traffic is concerned, is found to be one-fifth of the entire width of street. It is scarcely necessary to add that vehicles pass each other on the left side, pedestrians on the right. It is not easy to assign a cause for the former beyond custom, except that the whip is held in the right hand, and in consequence free play is given for its use as the driver sits on that side and can watch his wheels in passing. In France and other countries the right side is the “rule of the road.” In the case of pedestrians it is perhaps more convenient for many reasons to pass on the right side, one being that the umbrella or parasol is always carried in the right hand, which is also used to remove the hat when bowing, and another because one’s tendency in passing any obstacle is to give way with the left shoulder. For regulating the traffic and for the protection of foot passengers, “sanctuaries,” as they are termed, have often to be constructed by surveyors in broad streets or awkward centres of traffic, and it is well to place a lamp-post on these sanctuaries, on which may be advantageously fixed a notice, “Keep to the Left,” so as to regulate vehicular traffic. On the lamp-posts at the edge of the footpaths it is also sometimes customary to fix small enamelled iron plates bearing the inscription on both sides, “Keep to the Right,” so as to regulate the pedestrian traffic.
Of the danger to life and limb to pedestrians in London much has frequently been said, and no wonder, when we consider the number of persons who are daily injured and sometimes killed according to the Registrar-General’s returns. Some years ago it was proposed to erect light iron bridges over the most dangerous crossings approached by winding stairs, but “time is money” in the mighty metropolis, and the scheme was abandoned because it was felt that most persons would prefer the risk of being run over rather than spend the time in ascending and descending the necessary steps for this purpose.