now, however, but of rare occurrence; and it is more than probable, that the great improvements which have been made in the boiler and safety-valve will effectually secure these parts of the engine from a recurrence of such tremendous explosions as characterised the first introduction of steam navigation. And, lastly, the political economist must hail with the most heartfelt gratification, the introduction of so able and efficient a substitute for animal labour as the steam-engine. For it has been calculated that there are at least ten thousand of these machines at the present time at work in Great Britain, performing a labour more than equal to that of two hundred thousand horses, which, if fed in the ordinary way, would require above one million acres of land for subsistence; and this is capable of supplying the necessaries of life to more than fifteen hundred thousand human beings.[11] [11] _Vide_ Historical Account of the Steam-engine, by C. F. Partington. An ingenious foreigner, who lately visited England, has published an estimate of the mechanical force set in action by the steam-engines of this country. He supposes that the _great pyramid_ of Egypt required for its erection the labour of more than 10,000 men for 20 years:--but if it were required again to raise the stones from the quarries, and place them at their present height, the action of the steam-engines of England, which are managed at most by 36,000 men, would be sufficient to produce the same effect in 18 hours. THE END. LONDON: PRINTED BY C. ROWORTH, BELL YARD, TEMPLE BAR. * * * * * Transcriber's note: Minor typographical and punctuation errors have been corrected without note. Irregularities and inconsistencies in the text have been retained as printed. The cover for the eBook version of this book was created by the transcriber and is placed in the public domain. On pages 84 and 85 there are two items both of which are numbered LXXXVIII. The table of contents reflects the same. In the table of contents the following page numbers have been changed to match the book: Page lxxxii: 33. A Needle Alphabet--39 changed to 38 38. A Sieve Alphabet--ibid. changed to 41 Page lxxxiv: 79. A total locking of Cabinet Boxes--78 changed to 77 80. Light Pistol Barrels--ibid. changed to 78 End of the Project Gutenberg EBook of The Century of Inventions of the Marquis of Worcester, by Charles F. Partington