Evelyn, in his Diary, informs us on the 1st of August, 1666, “I went to Dr. Keffler, who married the daughter of the famous chymist, Drebbell, inventor of the bodied scarlet.” On which his editor, Mr. Bray, remarks, “Cornelius Van Drebbell, born at Alkmaar, in Holland, in 1572; but in the reign of Charles I. settled in London, where he died in 1634. He was famous for other discoveries in science--the most important of which was the thermometer. He also made improvements in microscopes and telescopes; and though, like many of his scientific contemporaries, something of an empiric, possessed a considerable knowledge of chemistry, and of different branches of natural philosophy.”--Diary, vol. ii. p. 9. Pepys, in his Diary, under date the 14th of March, 1662, says: “This afternoon came the German, Dr. Knuffler, to discourse with us about his engine to blow up ships. We doubted not the matter of fact, it being tried in Cromwell’s time, but the safety of carrying them in ships; but he do tell us, that when he comes to tell the King his secret, for none but the Kings, successively, and their heirs must know it, it will appear to be of no danger at all.”--Pepys’ Diary, ed. 1858, vol. i. p. 264. Dr. Robert Hooke, in his “Philosophical Collections,” published in 1679, has “an account of Jo. Alphon. Borellius’s De Mo. Animalium,” two volumes quarto, containing, among other things, “A way to make a submarine vessel, whereby several persons may pass together from place to place under water, accommodated with two ways to move it to and fro, and to make it rise and sink in the water, &c. It is supposed it may be much like that which Mersennus long since published.” The American engineer, Robert Fulton, turned his attention to this subject, and published “Torpedo War, and Sub-marine Explosions,” 4to. New York, 1810. 11. How to prevent and safeguard any Ship from such an attempt by day or night. [_How to prevent both._] Some armour or alarum is probably proposed, which should be either invulnerable, or when struck indicate the presence of the enemy’s “portable pocket engine,” intended “irrecoverably to sink the ship;” not by merely perforating a single hole, but by a powerful disruptive explosion, rending asunder all the timbers. But the whole passage is so abundantly obscure that all opinion on the matter goes for very little. 12. A way to make a Ship not possible to be sunk though shot[4] an hundred times betwixt wind and water by Cannon, and should[5] lose a whole Plank, yet in half an hours time should be made as fit to sail as before. Footnotes [4] shot at. P. [5] she lose. P. [_An unsinkable Ship._] As early as 1583, appeared “A Note of sundry sorts of Engines,” without the author’s name. The 20th and last of these is:--“To preserve a boat from drowning and the people that be therein.” See J. O. Halliwell’s Rara Mathematica.