Mr. MacGregor, greatly to his credit, desirous of ascertaining whether this report (which, from the well-known accuracy of M. de Navarette on other subjects, had been accepted as correct) could be depended upon, visited Spain in September, 1857, and made a thorough investigation at Simancas, Madrid, and Barcelona into this interesting subject, but his inquiries (reported, at length, January, 1858, to the Superintendent of Specifications at the Great Seal Patent Office, and printed in Part II., “Specifications relating to Marine Propulsion”), convinced him “that there was not one particle of reliable evidence” in M. de Navarette’s assertion.[15] An attentive consideration of the subject leads to the conclusion at which Mr. MacGregor has arrived. Even in the present day it would require an engine and boiler of considerable size to propel a vessel of 200 tons three miles an hour; moreover, the novel and bulky machinery with which the experiment is said to have been made, could not have been erected in the ship or removed from her without attracting considerable public attention. Indeed, had such an experiment been made before the Spanish Emperor, and made successfully as the narrative leads us to suppose, a matter so important could hardly have lain dormant for any great length of time: whatever, therefore, Blasco de Garay’s invention may have been, it was evidently not a steam-engine practically applicable for any useful purpose. Witzen, no doubt, in confirmation of Garay’s experiment, furnishes an illustration of a “Spanish bark without oars or sails,” but as, unfortunately, there is not a single line of letter-press beyond the few words quoted to throw the faintest light upon his drawing, it can only be supposed from the descriptive title that it referred to the vessel which Garay is said to have propelled. Indeed, De Garay’s whole story looks very much as if it was an invention of the Spaniards; Mr. Scott Russell,[16] as well as Mr. MacGregor, is of this opinion, and Mr. Woodcroft, no mean authority on such matters, states that, having made diligent inquiries at Simancas, he could find no trace of these documents, thus confirming the result of the more minute researches of Mr. MacGregor.[17] [Sidenote: Progress of invention; Bourne, Solomon de Caus, Marquess of Worcester, &c.]