The History of Science from the days of Archimedes presents a vast phalanx of men mighty in genius; but foremost in this intellectual group ranks the Marquis of Worcester, the originality, independence, and grandeur of whose mechanical conceptions have acquired a world-wide celebrity; for he it was who first evoked that Titanic power, which, through successive improvements, consequent on the accumulated ingenuity of two hundred years, has given to the present age the modern Steam-engine. It may be freely conceded that, _stupendous_ as he himself pronounced the parent engine to be, it was, nevertheless, only as the acorn compared to the time-honoured monarch of the forest. Just as the existence of the plant is dependant on that of the seed, so, had the Engine he constructed never existed, we might have been unacquainted even to this day with the mechanical application of steam. Living at a period when Civil War convulsed this country, and unhappily brought severe suffering on all who were conspicuous for their loyalty, the Marquis of Worcester, in common with the Royalist party, had to succumb to intolerant rulers. For while Cromwell enjoyed an income of £2,500 per annum, derived from a portion of his Lordship’s princely estates, the Protector proudly granted to THE INVENTOR OF THE STEAM ENGINE, a weekly stipend of Three pounds! Unfortunately, the Restoration of the monarchy contributed but little to ameliorate his Lordship’s sad condition; while his enthusiasm led him to sacrifice those personal comforts which his declining years would seem to have absolutely required; rather than jeopardize operations depending on his great invention. In offering for your Grace’s approval this first effort to realize a connected memoir of your Grace’s immortal ancestor, it is unnecessary to dwell on the fact of its matter being chiefly derived from very scattered sources, and often from but fragmentary materials, though in every instance the very best available authorities have been consulted; among which, the unique collection of Manuscripts, so freely and obligingly submitted for the present purpose by your Grace, being given entire, forms the most valuable and interesting portion. I sincerely regret my own insufficiency to do complete justice to this comprehensive labour. The result of my researches, however, may gratify your Grace’s curiosity, and prove interesting in respect to many early family details. And if my own earnestness of purpose, in prosecuting this attempt, does not mislead me, I may venture to hope, that the Memoir will not only meet with your Grace’s favourable reception, but prove, at the same time, acceptable to the general public. With warm acknowledgments of heart-felt obligation to your Grace, for the exceedingly handsome and liberal manner in which manuscripts and paintings have been placed at my disposal,