Gunpowder, is the Force of the Powder acting upon the Ball, both during its Continuance in the Barrel, and to fome Distance beyond the Muzzle. In the next Place our Author proves thefe Propofitions; First, That the Altitude to which a Project rifes, is as the verfed Sine of the doubled Angle of Elevation. Secondly, That the Time of the Flight of a Project, thrown with a given Velocity, is as the Sine of the Angle of Elevation. He fhews afterwards how the Velocity, wherewith a Project is thrown, may be difcovered from Trials; and he obviates an Objection which may very plaufibly be made to this Method. At the Clofe of this Difcourfe we have a Table exhibiting a Set of Experiments concerning Projects made with a fmall Mortar. The twelfth, thirteenth, and fourteenth Lectures are altogether HYDROSTATICAL. In the first of thefe we have both a theoretical and experimental Account of the Gravitation and Preffure of Water, and fuch other Fluids as are commonly called Liquids. In the fecond we have the Rules neceffary for difcovering the Denfities and specifick Gravities of Bodies. In the third we have Directions for computing the Flux of Water from Refervoirs of various Dimenfions, through Orifices and Pipes of different Sizes. The fifteenth and fixteenth Lectures are Pneuma❤ tical. In the former of them our Author has infifted on the Weight and Preffure of the Air, and defcribed fome remarkable Effects arifing therefrom. In the latter he confiders that more wonderful Property of the Air, its Elafticity: Or that Force wherewith the Particles of it expand themfelves, and recede from each other, whenever the Preffure from without, which keeps them together, is taken off. The Method which he observes in the Profecution of this Point is, Firft, to fhew from Experiments, that the Air is really endued with fuck fuch a Force; and, Secondly, to inquire into its Nature and Laws. The feventeenth Lecture explains the Nature of Sounds, and then treats of the Vibrations of mufical Strings. Sounds, our Author fays, confidered in their phyfical Caufes, are nothing elfe but the Pulfes of the Air: There are five Properties of these Pulfes which he diftinctly infifts on in order to explain the Nature of Sound, and forms thereupon a curious harmonick Theory: One Part of which fhews us in what Proportions the Times of the Vibrations of mufical Strings are varied, by varying the Length, Thickness, or Tenfion of the Strings. As in the feventeenth Lecture, of which I have now been speaking, Dr. Helfham, in treating of that Motion of the Air which is productiue of Sounds, has made it appear, that each Particle of Air, in going forward and returning back, is twice accelerated, and as often retarded; in the eighteenth he inquires into the Law of that Acceleration and Retardation; and exhibits a formal Demonftration of the third Property, which he attributes to the Pulfes of the Air above-mentioned. He has here taught us with great Exactnefs to discover the Space through which Sound moves in a Second of Time; and thence also to find the Length of the Pulfes excited by the Vibrations of a founding Body, provided the Number of Vibrations performed by the founding Body in a given Time can by any Method be determined. In the nineteenth Lecture, on LIGHT, the Doctor, after a general Definition thereof, defcants a Jittle on its ftupendous Velocity, and then more largely infifts on its Refrangibility. He has evinced the bending of the Rays in their Paffage out of one Medium into another, which is ufually termed their Refraction, to be owing to the attractive Force of the denfer Medium acting upon the Rays at right Angles to the Surface. The Subject of this Lecture prepares prepares the Reader for the Understanding of the twentieth, which treats of Colours, and the Phoenomena of the Rainbow.. The twenty-firft, twenty-fecond, and twenty-third Lectures, which are the laft, relate entirely to Vifion, either direct, reflected, or refracted. That which explains the Nature of Vifion, and is the fecond of thefe, fhould, I prefume, of right, have been the firft of the three. But our Author has chofen a different Difpofition, and given that the Precedence which confiders the chief Properties of dioptrick Glaffes; as he has placed that laft which contains the Science of Catoptricks, or that Part of Opticks which treats of the Reflection of Light. ARTICLE V. LETTERS concerning Poetical Translations, FE 1739. EW Treatifes of no greater Bulk contain fo many curious and beautiful Obfervations as this before me. The Writer has difcovered therein an uncommon Delicacy of Genius, and a more than ordinary Intimacy with the Mufes. He has given the Bulk of his Readers an Idea of Virgil entirely new, and has unveiled the Fountains of that Pleafure which never fails to accompany the Perufal of his divine Writings, but which were utterly unknown to Thousands who participated of it. Innumerable Graces in that Poet, and in our own immortal Milton, before imperceptible to common Eyes, fhine thro' his Illuftrations; fo that tho' nothing can perhaps be added to their intrinfick Excellence, our Delight in converfing with them is inhanc'd as that becomes obvious. Our Author has comprized his Sentiments in ten Letters. In the first he lays down, and defcants upon, a fundamental Rule, by which every one is to conduct himself, who would fucceed in the Bufinefs of a Tranflator: That is, to confider, and ftrictly regard in bis Verfions, the peculiar Stile of the Origi nal be tranflates. In treating of this Matter he points out the diftinguishing Properties of Homer's and Virgil's Diction. His Brevity on this Head does not hinder him from handling it with great Perfpicuity. His Method of exemplifying the feveral Propofitions he advances, enables us to form the most exact and explicit Notions of his Subject. His Examples (wherein we behold the Rapidity of Homer, and the Sufpence and Majefty of Virgil) are borrowed, as I apprehend, from the Rev. Mr. Pitt's English Tranflations of the Eneid and Iliad. In a Poftscript to this Letter, he makes fome judicious Remarks on the Speech of Apollo's Prieft at the Entrance of the Iliad; this, he fays, is won. derfully peinturefque and in Character. He takes particular Notice of an Expreffion therein, that he regards as one of the finest in all the poetical Language: To give to do a Thing. And he tells us, Virgil was fo fenfible of the charming Effect of it, that he has it three or four times in the very first Eneid: Inftances of which he produces. The next Letter contains a Variety of curious Reflections, occafion'd by the fecond Line in Mr. Pitt's Tranflation of the Beginning of the Iliad above-mentioned; wherein the auxiliary Verb did is 'made ufe of. The Line runs thus: "Which to the Greeks did endless Sorrows bring. Many, Many, it seems, have erroneoufly fancy'd, that all auxiliary Verbs are abfolutely condemned, as mere Expletives, by Mr. Pope, in his Effay on Criticisms Where he says, "While Expletives their feeble Aid do join, But as our Author believes Mr. Pope never intended to advance fuch a Doctrine, fo, on the other Hand, he notes, that Milton has ufed them in fundry Places where he could have avoided them if he had pleased; which Practice can be accounted for only on the Suppofition of his thinking they added Strength to the Expreffion: Our Author is of the fame Opinion, and is pofitive they do fo; excepting. where the auxiliary Verb is brought close to its Principal, and that a thin Monofyllable, as in the Line just now referr'd to. When he has by divers Authorities evinced the Advantage of the auxiliary Verb to the poetick Style, and induced us to grant it would be a great Lofs to English Poetry if it were to be wholly laid afide, that in Tranflations from the Greek and Latin it would be fometimes impoffible to do juftice to a Writer without the Help of it, and, in a Word, that Expletives are not only juftifiable, but even in fome Cafes neceffaryThings; he proceeds to fay fomething of Monofyllables, generally confider'd, against which many have been prejudiced by Mr. Pope's Cenfure of them, (as they apprehend it) in the second of the two Verfes juft cited from his Effay: "And ten low Words oft creep in ove dull Line. In vindication of thefe he alledges, that Hundreds of Lines, compofed of them only, are to be found in Milton, as fublime, as beautiful, and as harmo |