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How you may Arithmetically know how much wide, ouer, or short, any peece of Ordinance will shoote from the marke, by knowing the distance to the marke, and how your peece is laid to shoote at the said marke.
Question.
If a Culuering or Cannon of 10 foote long, be shot at a marke 700 yardes from the peece, the mouth of the said peece planted an inch wide, how far shall the bullet light wide of the marke?
Resolution.
Reduce the measure of the length of the peece into inches, because the denomination of widenesse is by in∣ches, and the peece of 10 foote length, will yeeld 120 inches. Likewise reduce the length from the peece to the marke into inches, you haue 25200 inches. Then by the rule of propotion: say, if 120 inches shoot wide one inch, what will 25200 inches? And in multiplying and deui∣ding according to the rule, you shall find in your quoti∣ent 210 inches, that is 17 foote ½: so much shall the bullet light wide of the marke. For this is a generall rule, that looke how many times the length of the cilinder or concaue of the peece is to the marke, so many inches shall the peece shoote amisse, being laid ouer one inch, or vnder, or wide of the marke, if the winde doe not alter it. The like is to be done of any other.