A discourse on the theory of gunnery. : Delivered at the anniversary meeting of the Royal society, November 30, 1778. / By Sir John Pringle, baronet. Published by their order.

John Pringle

Date:: 1778

Credit: A discourse on the theory of gunnery. : Delivered at the anniversary meeting of the Royal society, November 30, 1778. / By Sir John Pringle, baronet. Published by their order. Source: Wellcome Collection.

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$- T ^ * hypothefis, repugnant to all the laws of motion, to falve appearances, and to reconcile thofe experiments with his former doctrine ' V , i / y . ' • . ' * And did not Dr. Halley, fo long the ornament of this Society, communicate in the year 1686 a Paper, which he calls Adifcourfe concerning gravity, in which, treating of the motion of projectiles, he fays, that being aware of the deflexion from the parabolic curve that might be occafioned by the refiftance of the air, he had made fome experiments, even with cannon-balls, to ef- timate the force of that refiftance; yet conclude, 'that hi large Jhot of metal, whofe weight many thoufand times fur- paffed that of air, and whofe force is very great, in pro¬ portion to the furface wherewith they prefs thereupon, this oppoftion was not difcernible. And again, ithough in fmall and light Jhot, the oppofition of the air ought and nwjl be accounted for; yet in fhooting great and weighty bombs, there need be very little allowance made; and fo thefe rules [thofe, to wit, grounded on the principle of Galileo] may be put in praBice to all intents and purpofes, as if .this impediment [the refiftance of the air] were abfolutely » . ’ t , . . 1 \ . * * (n) See his treatife To hit a Mark, publifhed in 1690. removed\$