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THEORY AND PRACTICE

TRACT 37*

it appears in the table, that 8 ounces of powder dischargethe lib ball with 1600 feet velocity; and because 8lb are ==128 ounces; therefore by the rule, as : v'VV : : 1600 :1600^/^4 = 1600 v'-| =1306, the velocity sought.

97. Otherwise. Say, as the root of the weight of the shot,is to the root of double the weight of the powder, so is 1600to the required velocity. That is, in the present example,as v'24 : V\6 :: 1600 : 1306, the same velocity.

98. But when the charges bear the same ratio to oneanother as the weight of the balls, that is when the piecesare said to be alike charged, then the velocities will be equalnearly. Thus, the lib ball by the 2 oz charge, being the8th part of the weight, and the 24lb ball, with 3lb of pow-der, its 8th part also, will have the same velocity, viz, 800feet. In like manner, the 1200 tabular velocity, answeringto 4 oz of powder, the 4th part of the ball, will nearly be-long to the 24lb ball with 6lb of powder, being its 4th part,and the tabular velocity 1600, answering to tire 8 oz charge,which is \ the weight of ball, will equally belong to the 24lbball with 12lb of powder, being also the \ of its weight.