We may indicate a few of the alterations.  In 1829 the cylinders were set at a steep angle; in 1830 they were nearly horizontal.  In 1829 the driving wheels were of wood; in 1830 they were of cast iron.  In 1829 there was no smoke-box proper, and a towering chimney; in 1830 there was a smoke-box and a comparatively short chimney.  In 1829 a cask and a truck constituted the tender; in 1830 there was a neatly designed tender, not very different in style from that still in use on the Great Western broad gauge.  All these things may perhaps be termed concomitants, or changes in detail.  But there is a radical difference yet to be considered.  In 1829 the fire-box was a kind of separate chamber tacked on to the back of the barrel of the boiler, and communicating with it by three tubes; one on each side united the water spaces, and one at the top the steam spaces.  In 1830 all this had disappeared, and we find in Mr. Nasmyth’s sketch a regular fire-box, such as is used to this moment.  In one word, the Rocket of 1829 is different from the Rocket of 1830 in almost every conceivable respect; and we are driven perforce to the conclusion that the Rocket of 1829 never worked at all on the Liverpool and Manchester Railway; the engine of 1830 was an entirely new engine.  We see no possible way of escaping from this conclusion.  The most that can be said against it is that the engine underwent many alterations.  The alterations must, however, have been so numerous that they were tantamount to the construction of a new engine.  It is difficult, indeed, to see what part of the old engine could exist in the new one; some plates of the boiler shell might, perhaps, have been retained, but we doubt it.  It may, perhaps, disturb some hitherto well rooted beliefs to say so, but it seems to us indisputable that the Rocket of 1829 and 1830 were totally different engines.

[Illustration:  Fig. 1.  The rocket, 1829.  The rocket, 1830.]

Our engraving, Fig. 1, is copied from a drawing made by Mr. Phipps, M.I.C.E., who was employed by Messrs. Stephenson to compile a drawing of the Rocket from such drawings and documents as could be found.  This gentleman had made the original drawings of the Rocket of 1829, under Messrs. G. & R. Stephenson’s direction.  Mr. Phipps is quite silent about the history of the engine during the eleven months between the Rainhill trials and the opening of the railway.  In this respect he is like every one else.  This period is a perfect blank.  It is assumed that from Rainhill the engine went back to Messrs. Stephenson’s works; but there is nothing on the subject in print, so far as we are aware.  Mr. G.R.  Stephenson lent us in 1880 a working model of the Rocket.  An engraving of this will be found in The Engineer for September 17, 1880.  The difference between it and the engraving below, prepared from Mr. Phipps’ drawing, is, it will be seen, very small—­one of proportions more than anything else.  Mr. Stephenson