GUNNERY THE Italians seem to have been the first people that di rected their attention to the subject of the motion of can non shot. Nicholas Tartaglia, a Venetian, who was born at Brescia, published at Venice, in 1537, his Nuova Scieuza, and in 1546 his Qziesiti e Invenzioni diverse, in both of which he treats the subject of projectiles. In the last of these works, he gives an account of the calibre rod, or ar tillery measuring rod, of which he seems to have been the inventor. In another ‘voi k, translated into English by Cy prian Lucas, and entitled Colloquies concerning the Art of Shooting in Great and Small Pieces of Artillery, Lond. 1588, he has entered more minutely into the subject. Having no knowledge of the practical part of artillery, Tartaglia investigated the subject theoretically upon fallacious prin ciples, and can scarcely be considered as having done any great service to this branch of science. He is supposed, however, to have discovered that projectiles may be thrown to the greatest distance when they are projected at an angle of 45 degrees ; and, in opposition to the notion of practical gunners, he maintained that no part of the path of a cannon ball was a straight line, but that it was like the surface of the sea, which, though to all appearance a plane, was ne vertheless a portion of a circle described by the radius of the earth. Tartaglia appears also to have been the inven tor of the gunner's quadrant.
The researches of Tartaglia, imperfect and unsatisfac tory as they were, had the merit of directing the attention both of military engineers and mathematicians to this curi ous subject. Many fallacious theories of the motions of cannon shot were brought forward, and Ufano, Galeus, Ul rick, and several other writers, puhlished tables of the comparative ranges of military projectiles, that were quite irreconcileable with experiment.
The first experimental examination of this subject was made by M. Collado, a Spaniard, who served as an engineer with the Spanish army in Italy. In his wotk entitled Prac tica Manuale de Artiglieria, Venice, 1586, which was first published in Italian, and afterwards in Spanish, he has given for each point of the gunner's quadrant the ranges of a falconet which carries a three pound shot. Mr Robins remarks, that it is manifest, from the number, that the fal conet was not loaded with the usual quantity of powder. The following are Collado's results : The next experiments which were made on this subject, appeared in the Art of Shooting in Great Ordnance, a work which was published in 1643 by Mr William Bourne. He
assumes unity as the range for a point black shot, and as certains the ratio of the ranges at different elevations. Bourne does not mention the nature of the piece which he used, but Mr Robins presumes that it must have been a small one. The following Table contains the results given in Chap. vii. of the above work : A very admirable series of experiments were made early in the 17th century, by our countrymen Eldred, who was for many years roaster gunner at Dover castle. His ear liest experiments are dated MI; hut the book which con tains them, entitled The Gurner's Glasse, was not publish ed till 1646. His experiments, which are very numerous, were made with great care, and the principles on which he proceeded were simple and tolerably correct. He has pub lished the actual ranges of different pieces of artillery, at small elevations, nut exceeding ten degrees, and among these are some trials made with the famous cannon called the Gasilisk, a piece 23 feet long, and well known to those who castle. He found that this gun, which carries a 10 lb. shot, ranged 3600 feet with 18 lb. of powder, at an inclination of 2^, and 6000 feet at an elevation of 43°.
The subject of gunnery was now destined to receive the most important improvements from the genius of Gali leo. By the application of mathematics to the doctrines of motion, he has given the form of a science to this branch of natural philosophy, and has enabled us to ascer tain every thing that relates to the flight of military pros jectilcs, on the supposition ghat they are discharged in a non-resisting medium. His Discursus et Demonstrationes Mathenzaticic, &c. which contain these fine investigations, were published in 1638. They are given in the fourth dialogue, entitled De Motu Projectorum, and occupy four teen propositions, in which he has proved, that a projectile must describe a parabolic curve by the combination of the force of gravity with the force of projection, and has shown how to compute the distance to which the body will be thrown, the time of its flight, and the momentum with which it falls, when projected in a given direction, and with a given velocity. Galileo was perfectly sensible that the resistance of the air would produce a considerable change in these results, and he has described a method of discovering the magnitude of the effects which this resistance would produce on the motion of a bullet at some given distance from the gun.