explains the plan adopted in indicating the several inventions, and in no way detracts from the value of the work. The Inventions may be thus classified: 3 refer to Seals and Watches. 2 . . . Games. 2 . . . Arithmetic and Perspective. 6 . . . Automata. 23 . . . Ciphers, Correspondence, and Signals. 10 . . . Domestic affairs. 9 . . . Mechanical appliances. 32 . . . Naval and Military affairs. 13 . . . Hydraulics and the Water Engine. --- 100 The very incongruous character of these matters is suggestive of their having occurred to the inventive mind of the Marquis at very different times, at remote intervals, and under varied circumstances; they might occasionally have resulted from his reading, his studies, or his experiments. He evidently availed himself of every suggestion that either reading, accident, experience, or travel threw in his way. His domestic life led to light, amusive, and mechanical exercises; while his military operations drew him to consider improvements in ordnance, fire-arms, and military and naval affairs generally. All we know regarding the origin of the work itself is derived from the author’s title page, wherein he states that it was written in 1655, his “former notes” then “being lost.” He consequently sets down “at the instance of a powerful friend,” only those inventions he “can call to mind to have _tried and perfected_.” This explicit language admits of no doubtful construction, yet he has been maligned by the envious as recording dreams and fancies. The Century closes with the remarkable declaration of his “meaning to leave to posterity a book, wherein under each of these heads the means to put in execution and visible trial all and every of these inventions, with the shape and form of all things belonging to them, shall be printed by brass-plates.” An intention which his premature decease rendered unavailing, yet sarcastic writers have not been wanting to stigmatize the “Century” as though its author had offered it to public approbation as a complete work; making no allowance for the circumstances under which it was produced, as a mere syllabus of the intellectual treasures he possessed, or the sad occurrence to which alone the non-completion of his promised publication with engravings of his several designs can be attributed. Some of his inventions he specially notices to signify their practical development. Thus No. 56, he performs at the Tower before Charles I, most of his Court, and the Lieutenant, Sir William Balfour. No. 64, an improvement on fire-arms, was “tried and approved before the King (Charles I.), and an hundred Lords and Commons.” Nos. 59 to 67, further improvements on fire-arms and cannon, occasion his particularly stating that:--“by several trials and much charge I have perfectly tried all these.”