How to make a good shot in a peece that is not truly bored: or to know how much any peece will shoote amisse, that is thicker of mettall on the one side then on the other, if you know the di∣stance to the marke.
Question.
A certaine Gunner hauing shot diuers times in a Cannon at a marke supposed to be 500 paces from the peece, findeth she shooteth still towards the right hand, & searching whether the fault were in him selfe, or some impediment in the peece, he findeth that the peece is 2 inches thicker of mettall on the right side then on the left. And therefore requesteth how to lay the concaue of the peece (being 9 foote in length) equall with the marke, so as he may make a straight shot.
Resolution.
To do this or the like, there is a generall rule, that looke how oftentimes the length of the cilinder or con∣caue of the peece is to the marke, which is easily done by deuiding the distance to the marke, by the length of the concaue of the said peece. And knowing likewise how much the one side of the peece is thicker then the other, the one halfe of that ouerplus being multiplied by the quotient first found, the product will shew you how