Motion is communicated to the driving wheels by a double set of spur wheel gear, arranged to give different cowers or velocities, by having both a large and a small wheel fixed on the driving as well as the driven axis. By shifting the large wheel on the driving axis into gear with the small wheel or the driven axis, speed is obtained ; and by shifting their relative position till the small wheel on the driving axis comes into gear with the large wheel on the driven axis, power is obtained at the expense of speed. These two axes are kept at the same distance from each other by means of connecting rods, notwithstanding the relative position may be changed by the motion of the carriage on rough roads.
These patentees do not claim novelty in any one of their arrangements in a detached form, but only the combination of the whole, as they have described them in their specification. A principal merit of the arrangement seems to be, that all the adjustments are brought within reach of the man having the guid ance of the carriage.
An American inventor communicated to Mr. Gillet of Birmingham a new modification for a carriage or waggon, for which the great seal was obtained on the 4th of November 1830. The invention consists in the adaptation of the wheels of carriages to what has been called a perpetual railway. It is formed by a circular rib or rail placed round the interior of the felloe of the wheel, upon which circular rib a small wheel with a grooved periphery is intended to run, which small wheel bearing its portion of the burthen of the carriage, by running upon a smooth even surface, it is presumed will greatly facilitate the progress of the carriage, when the larger or running wheels pass over heavy or uneven ground. In the annexed cuts are represented by Fig. 1 a side elevation of the large running wheel, and the situation of the smaller one that runs on the inside of its felloe ; and 4. 2 shows a sectional end view of two such wheels, with their little companions, applied to a tram waggon ; a a is a large wheel of a common description, and turning loosely (with considerable play) on the axles b b, which is made in the form represented to obtain considerable strength, and having strong curved arms which form the axes of the little wheels c c; these are grooved on their peripheries to fit the circular edge railways d d, fixes inside the felloes of the large wheels. The patentee states that "although the running wheels will pass over the ground as in ordinary carriages, yet the weight of the carriage and its burthen is borne by the small wheels, and consequently, through the large running wheels should pass over soft, wet, or uneven ground, the wheels which actually bear the weight, and upon which the carriage travels, move upon a smooth, even perpetual railway on which there is little or no resistance." The patentee, however, omits to notice the obvious fact, that the little wheel does not assist the great wheel out of the mire, but rather tends to sink it deeper by reason of its weight and the heavy incumbrances it entails, to say nothing of the extra friction caused by an unnecessary increase of rubbing surface in the multiplied axles.
"This contrivance," the patentee adds, "is equally applicable to the wheels of any kind of carriage, and is only shown in the drawing as adapted to a tram waggon for the purpose of illustrating its peculiar construction and adaptation." A similar invention was patented by Mr. George Hunter of Edinburgh in 1826.
Messrs. Bramley and Parker, of Moulsley Priory, in Surrey, received patent grants for their improvements in locomotive carriages, applicable to rail and other roads; which we shall very briefly describe, as they do not appear to us likely to become of much practical utility in the present state of the art of locomotion. The improvements contemplated are of three kinds. The first
consists of a carriage to be propelled by horses, working a pair of tread-wheels ; the second of a light carriage to be propelled by one or more men, resting with their chests on cushions, and communicating motion to cranks by pushing out with their feet, si in the act of swimming ; the third consists of an arrangement for preserving the box of the wheel on the end of the axle. The latter plan is very deficient in novelty; • the other two are modifications of many similar propositions to obtain mechanical force from animal agency ; but we cannot agree with the ingenious patentees that they are "certain improvements." The detail, of these inventions, with the amusing illustrative drawings, may be seen at the " Six clerks' office " in Chancery-lane.
Mr. Gordon, in his Treatise on Locomotion, page 58, states, that in the beginning of the year 1831, the directors of the Monkland and Kirkintilloch railway, near Glasgow, directed their engineer to make out • San and specification of two locomotive engines, able to drag 60 tons gross weight at the rate of 4 or 5 miles an hour. This was done accordingly, and the engines contracted for by Messrs. Murdoch and Aitken engineers, Hill-street Glasgow, who brought the first upon the railway the 10th of iday, and the second upon the 10th of Sep tember the same year. Both engines travelled several miles upon the railway ; the first day they were brought out of the yard at Glasgow, and have since, during a course of eighteen months' trial, proved themselves the most efficient engines of the kind ever made in the kingdom, being capable of taking 10 tons more on a level railway, than any engine yet made of the same size of cylinder with a pressure of 501bs. to the square inch upon the boiler. The line of railway on which these engines daily travel is one of the very worst description for the effectual working of such engines, being 13i miles in length, with numerous abrupt curves and descents. The descents are 1 in 50, 1 in 116, 1 in 120, &c. ; the curves are of a radius of 344, the arch 335 feet; radius 400 feet, arch 650; radius 700 feet, arch 545 feet, &c. The descents being in favour of the load, the bringing up the empty waggon is considered the heaviest work, yet one of these engines has frequently returned from Kirkintilloch, where the railway ends, with 50 empty waggons, in the ordinary course of trade, the weight of which being about 60 tons ; but when loaded, they carry a gross weight of about 200 tons. The daily load of engine, is from 20 to 50 loaded waggons, according to the circumstances, and trade occurring on the road. One of the great improvements on these engines is, the metallic packing of the pistons, which are the first of the kind ever used, and of such a description, that the 2 engines have not cost one shil big in 18 months for packing. and use neither grease nor any other unctuous substance whatever for the cylinders, since their commencement : another, and perhaps the greatest advantage of these pistons, is the economy of labour, the reduction of friction, and the saving of fuel thereby effected, the area the fireplace being just 4 feet, or one-half of the size of that in the Liverpool engines. These pistons are each formed of two iron rings in three segments ; a wedge between each segment is pressed by a spiral spring.