Note 70 — Chapter V · Early History of the Locomotive—George Stephenson begins its Improvement.

Mr. Zerah Colburn, in his excellent work on ‘Locomotive Engineering and the Mechanism of Railways,’ points out that Mr. Davies Gilbert noted the effect of the discharge of the waste steam up the chimney of Trevithick’s engine in increasing the draught, and wrote a letter to ‘Nicholson’s Journal’ (Sept. 1805) on the subject. Mr. Nicholson himself proceeded to investigate the subject, and in 1806 he took out a patent for “steam-blasting apparatus,” applicable to fixed engines. Trevithick himself, however, could not have had much faith in the steam-blast for locomotive purposes, or else he would not have taken out his patent for urging the fire by means of fanners. But the fact is, that while the speed of the locomotive was only four or five miles an hour, the blast was scarcely needed. It was only when high speeds were adopted that artificial methods of urging the fire became necessary, and that the full importance of the invention was recognised. Like many other inventions, stimulated if not originated by necessity, the steam-blast was certainly reinvented, if not invented, by George Stephenson.