N. B. Make your leaders of different lengths, or in cloathing of works, you will cut a great many to waste. Leaders for marron Batteries must be made of strong cartrige paper. SECT. V. Of Aquatick Fireworks. All works that shew themselves in the water, are much admired by most people who are fond of fireworks, particularly water rockets; but as these seem of a very extraordinary nature to those who are acquainted with this art, I shall endeavour to explain the method of making them, in as full and easy a manner as possible, as well as other devices for the water. Of Water Rockets. Water rockets may be made from four ounces, to two pound, but if larger they are too heavy, so that it will be difficult to make them keep above waters without a cork float, which must be tied to the neck of the case, but the rockets will not dive so well with, as without floats. Cases for water rockets, are made in the same manner and proportion as sky rockets, only a little thicker of paper; when you fill these rockets which are drove solid, put in first, one ladle full of slow fire, then two of the proper charge, and on that one or two ladles of sinking charge, then the proper charge, then the sinking charge again, and so on, till you have filled the case within three diameters; then drive on the composition, one ladle full of clay, through which make a small hole to the charge, then fill the case, within half a diameter with corn powder, on which turn down two or three rounds of the case in the inside, then pinch and tie the end very tight; having filled your rockets, (according to the above directions) dip their ends in melted rosin, or sealing wax, or else secure them well with grease. When you fire these rockets, throw in six, or eight at a time; but if you would have them all sink, or swim, at the same time, you must drive them with an equal quantity of composition, and fire them all together. To make Pipes of Communication, which may be used under Water. Pipes for this purpose, must be a little thicker of paper, than those for land works; having rolled a sufficient number of pipes, and kept them till thoroughly dry, wash them over with drying oil, and set them to dry; but when you oil them, leave about an inch and a half, at each end dry, for joints; for if they were oiled all over, when you come to join them, the paste would not stick, where the paper is greasy; after the leaders are joined, and the paste dry, oil the joints. These sort of pipes will lay many hours under water, without receiving any damage. Of Horizontal Wheels for the Water.