For JANUARY, 1811, Kept by ROBERT BANCKS, Mathematical Instrument Maker, in the STRAND, LONDON. * Intervening fogs. b Stormy. Boisterous. * Immeasurable, † and small rain, Erratum last Journal.-Dec. 25, for 29.31 read 29.00. A JOURNAL NATURAL PHILOSOPHY, CHEMISTRY, AND THE ARTS. MARCH, 1811. ARTICLE I. On the Motion of Rockets both in Nonresisting and Resisting (Continued from vol. XXVII., p. 285.) To Mr. NICHOLSON. SIR, ets. IN my last paper on Rockets I ascribed the invention of Invention of those now used by the English to Colonel Congreve :-My military rockassertion rests in the fact that this gentleman has been rewarded by government for the discovery; and my own conviction, that, anterior to such reward being granted, VOL. XXVIII. No. 128.-MAR. 1911. M a proper a proper enquiry could not but have been instituted concerning his pretensions. I herewith send you a further continuation of my essay on the motion, &c. of these machines, which I hope will be found worthy your acceptance; and am, Sir, Your much obliged humble servant, Royal Academy, Woolwich, Jan. 1811. W. MOORE. Path of a rocket in a nonresisting medium. PROP. II. To determine the path of a rocket near the Earth's surface, neglecting the resistance of the atmosphere. If during the time the rocket was on fire, the weight of the whole mass remained conftant, the path of the rocket would, by mechanics, be a straight line: but this being not the case on account of the continual wasting of the matter which feeds the flame of the rocket, the accelerative force of the body will be different at every instant; and therefore, since the accelerative force of gravity (as we will suppose) is constant to the height which rockets generally ascend, the rout of the rocket will consequently be a curvilinear one. Now, although gravity acts to impel the rocket from a straight course, yet it does not hinder the same from arriving at |