A practical treatise on coach-building historical and descriptive

by James W. Burgess

There has been much controversy about difference in the length of the front and hind axletree. It has been usual to make no greater difference than will allow the higher wheel to follow in the same track as the lower wheel. In France, however, it has been the practice since the year 1846 to make the front axletree of broughams 6 inches shorter than the hind ones. The object has been to allow the front wheel to be placed nearer to the body. As the front wheel of a brougham must turn entirely in front of the body, the additional gain of 3 inches was very desirable. Some English coach-builders have followed the example of the French. There is a decided gain. The eye is pleased with the proportions, the horse is eased, and upon hard roads the difference of track is of no consequence. On the other hand, in the country roads, the well-worn ruts make the running of the carriage uneasy, whilst in town the driver often forgets that the curbstones will strike his hind wheels sooner than his front ones, and also more mud is thrown upon the panels. Under these circumstances it is very probable that the French plan will not find universal favour.

If carriages had always to move along perfectly smooth roads such as a tramway of wood, stone, or iron, the use of wheels in overcoming friction would be their sole utility, and their height would be of small consequence. But as carriages are drawn along roads with loose stones and uneven surfaces, wheels are further useful in mounting these obstacles, and it is plain that a high wheel does this more easily than a low wheel. To demonstrate this, let us suppose a shallow ditch or gulley of a foot wide and 2 inches deep, a wheel 2 feet high would sink into this and touch the bottom, but a wheel 3 feet high would only sink an inch, and a wheel 4 feet 6 inches high would only sink half an inch (the wheels are supposed to cross the above-mentioned gulley at right angles), on account of their greater diameters. Consequently, while the large wheel would have to be lifted by a force sufficient to raise it half an inch, a force will have to be applied to the smaller wheel to raise it 2 inches, and under more disadvantageous circumstances, because the spokes are in this case the levers, and we know that the longer the lever the more easily is the load raised.

That the leverage power of a high wheel is very great is shown by the advantages gained by a large wheel in locomotives and bicycles.

There is an idea deeply rooted among coach-builders and coach-buyers too, that the draught of a vehicle is diminished by placing the front part of the carriage as far back as possible. Intelligent men who have given the subject great attention, and tested the actual working of this idea, say that it is a fallacy; but other intelligent men, who also say they have tested its working, say that it would effect a great saving in the draught if it were successfully accomplished. The general idea amongst practical men is, that it would not be an advantage. We have already seen that the draught of a vehicle with large wheels is less than that of a vehicle with small wheels. If, therefore, a load has to be placed on a four-wheeled vehicle, it should be so placed in relation to the front and hind wheels that the greater part of the weight should rest on the higher wheels. To obtain this result, it is sufficient to bring the hind-carriage part as far under the body as it will work with comfort and safety, in order that as little weight as possible rests on the fore-carriage part. English coachmakers have been working at this for thirty years, but for the most part blindly; they have copied well known builders in construction as well as shape; they hear that these well known firms’ carriages run and follow very lightly, and if they could copy accurately they would obtain the same reputation.

But while there is some doubt as to throwing the front wheels backward for the purpose of lessening the draught, Mr. Offord of Wells Street, Oxford Street, has been exercising his ingenuity for the purpose of throwing the back wheels further forward, and has produced a brougham that offers peculiar advantages in this respect ([Fig. 56]). The hind wheel appears to be placed right across the door, but the facilities for ingress and egress are quite equal to those given in the ordinary brougham. This novel contrivance presents nothing singular in appearance, while a very little reflection will satisfy the practical thinker that the advantage sought after, of lessening the draught of the carriage, must be obtained far more completely with this arrangement than by throwing the front wheel backward.

Fig. 56.—Single Brougham.

The rattling so constantly complained of in carriages can in a great degree be obviated by placing pieces of india-rubber so that the doors shall press upon them when closed; it is a good thing also to have india-rubber at the bottom of the doors for the windows to drop upon when let down.

The difficulty of protecting carriages from the dirt has recently been met by placing what is called a “mud scraper” just at the back of the hind wheels. It is formed of a piece of india-rubber about 3 inches square and a ¼ inch thick, held in position by a short iron rod attached to the end of the hind spring.

The elaborate dress carriages, hung with braces upon a C and under-spring perch carriage, require so much skill and practice in their manufacture that it is impossible to give ample directions for their construction in a work like this. Some years ago it was thought that no carriage could be made comfortable unless it was hung upon the old-fashioned perch carriage with braces; but it was found that by the introduction of india-rubber, especially in the ends of each spring, that what are termed elliptic spring carriages (which are of course much lighter in draught and less in cost) can be made extremely pleasant in motion.