TREVITHICK. 127 



nary stage-coach on four wheels, having one horizontal cylinder, 

 which, together with the boiler and fire-box, were placed at the 

 back of the hind axle. Mr. Michael Williams, late M.P. for Corn- 

 wall, in a letter to Mr. E. Watkins, dated the 5th of January, 1853, 

 mentions having been present at the first trial of Trevithick's loco- 

 motive, and says " the experiments made on the public road close 

 by Camborne were perfectly successful, and although many im- 

 provements in the details of such description of engines have been 

 since effected, the leading principles of construction and arrange- 

 ment are continued, I believe, with little alteration in the magnificent 

 railroad engines of the present day." After making several satis- 

 factory trials in the neighbourhood of Plymouth, Trevithick and 

 Vivian exhibited their invention publicly in London, first at Lord's 

 Cricket-ground, and afterwards on the spot of ground now occupied 

 by Euston Square.* At this latter place, however, Trevithick, in- 

 fluenced by some curious whirn, suddenly closed the exhibition on 

 the second day, leaving hundreds waiting outside in a state of great 

 wrath. Mrs. Humblestone, an old inhabitant of London, who at 

 that period used to keep a shop near to the present Pantheon, 

 Oxford Street, relates that she well remembers witnessing a public 

 trial of Trevithick's steam-carriage. On this occasion the shops 

 were shut, no horses or carriages were allowed in the streets, and 

 the roofs of the houses in the neighbourhood were crowded with 

 people, who hurraed and waived their handkerchiefs as the ' steam 

 monster ' was seen coming along Oxford Street at a rapid pace.f 



Two years afterwards Trevithick constructed the first successful 

 railway locomotive, which was used on the Merthyr Tydvil Railway 

 in the year 1804. This engine had an eight-inch cylinder, of four 

 feet six inches stroke, placed horizontally as at present, and working 

 on a cranked axle ; while, in order to secure a continuous rotatory 

 motion, a fly-wheel was placed on the end of the axle. When we 

 add to this, that the fly-wheel was furnished with a break, that the 

 boiler had a safety-valve or a fusible plug beyond the reach of the 

 engineer, and that the patent includes the production of a more 

 equable rotatory motion k ' by causing the piston rods of two cylin- 

 ders to work on the said axis by means of cranks at a quarter of a 

 turn asunder " it is scarcely too much to say that nothing material 

 was added to the design of the locomotive until the invention of the 



on record of oscillating engines. Sir John Eennie, F.K.S., in his address to the 

 Institution of Civil Engineers, in 1846, mentions the following passage: 

 " Even the objection of extra friction, however, if tenable, is obviated by the 

 vibrating cylinder described in Trevithick and Vivian's patent, in 1 802 ; patented 

 by Whitty in 1813, and by Manby in 1821, by whom the first engines of the 

 kind were constructed." 



* An eye-witness, who is still living, relates that on one of these trials he saw 

 Trevithick's steam-carriage proceeding at the rate of twelve miles an hour. 



f Mrs. Humblestone (1861) is now eighty-one years of age, and is residing in 

 the neighbourhood of Edgware Koad. 



