Three horses may have done the work in summer, but there is no reason to suppose that the roads of 1755 were any better than they had been sixteen years earlier, when Thomas Pennant thus described a journey in March from Chester to London. The stage, he says:— “was then no despicable vehicle for country gentlemen. The first day, with much labour, we got from Chester to Whitchurch, twenty miles; the second day to the Welsh Harp; the third to Coventry; the fourth to Northampton; the fifth to Dunstable; and as a wondrous effort on the last, to London, before the commencement of night. The strain and labour of six good horses, sometimes eight, drew us through the sloughs of Mireden and many other places.” [Illustration: TRAVELLING POSTING CARRIAGE, 1750.] THE APPLICATION OF SPRINGS. In the year 1768 Dr. R. Lovell Edgeworth, who had devoted much attention to the subject, and had made numerous experiments,[19] succeeded in demonstrating that springs were as advantageous to the horses of, as to the passengers in a coach; and he constructed a carriage for which the Society of English Arts and Manufactures awarded him three gold medals. In this conveyance the axletrees were divided and the motion of each wheel was relieved by a spring. Just one dozen patents for springs were granted during the eighteenth century, and it is impossible to say which invention had most influence on methods of building coaches. In 1772 a patent was granted to James Butler for a new coach-wheel the spokes of which were constructed of springs; but this curious contrivance is mentioned nowhere—so far as the writer’s investigations have shown—but in the Patent Office files, whence we may conclude it was a failure. [19] _An Essay on the Construction of Roads and Carriages._ London, 1817. [Illustration: TRAVELLING POSTING CARRIAGE, 1750.] The adoption of springs was certainly gradual. It is probably right to assume that wealthy men led the way by having coaches built on springs or altering their vehicles. It is impossible to draw a hard and fast line between the period of the coach without and the coach with springs. The illustrations show that travelling carriages on springs and braces were built in 1750. These drawings prove that, clumsy though the public conveyances were, private carriages were both tolerably light and comfortable. The “whip springs” to which the braces are attached were in general use ten years later. A curious error arose from the application of springs to public conveyances, according to Dr. Lovell Edgeworth. Their introduction, it must be premised, led to the accommodation of passengers and loading of baggage on top of the stage coach, and coachmen, finding the vehicle drew more easily, attributed the fact, not to the springs, but to the increased height and reduced length of the load.[20] [20] Abolition of the basket on the hind axle would have materially reduced the length of the load.