g^ -^HARGiSS OF GREAIBST EFFICACY FOR ARTILLERY AT SE4. 



Example IJ. 



Cafi$ ofbiirst- Required the" charge for a 24 pounder shot to burst opeii 

 inp open a ^ ^j,^ gates of a citj' with the greatest eas^ possible, the 

 pouwder. " ' ^,uU»tance of them beiii^elni 1 foot thick. 



Here the object to be penetrated being elm, the small 

 letters ir^ the general formula for the charge 



2Ds X 1600* 

 XXi.^ist be mgde to express the several numbers of some ex- 

 periment made in the penetration of this substance. Now 

 \>y a mean of ipany Yery accurate eJiiperiments made by 

 Pr. Button at Woolwich, in the years 1783, 1784, ancf 

 1785, be fo,u\id, that a cast iron ball of two inches diameter. 

 i(^npingii,ig perpendicularly oa the face of a block of eiror 

 V'.'Pod, with ti velocity of 1500 feet pe'' second, penetrated 

 13. inches de?p into it^ substance; hence we shall have. 

 (/ ^ ^ ft. V zz 150,0, a,nd s n |^ fi. ; also by the question 

 S == 1ft. D zz •AQ^, and w — 24lbs. Therefore. 



S <■/ »;^ w _ 1 X ^ X 150 0^ X 24 _ 45 X 9 

 Orps X 1600* ■*" 2 X -46 X TT X U'iOO* ~ JD4 X I'M 

 zz 3-50rt31 lbs. or 3 lbs. 8^ ozs. for the wi^ight of the charge 

 / • ?eqnired i,n this case. 



J^et.aining the experiment of Dr. Kfutton as a, standard 

 for all cases, where the object to. be penetrated is of el^n, we 

 Si^il! get bj' redaction 



Sdv"^ 10 ^ ^ S t^ 



^linmfl = •"«'<' "" -w 



the charge for any piece cf artillery the diameter of tht;, 

 shot of which is D, and weight tv ; S, being the thickness p^ 

 the object as before. 

 4 ,g j^j^y ^^ It i.s not unworthy of remark, that the gate of a besieged 

 Vii/.-it by th^e ' pl.ace., pr any like things, might be effectually broken open 

 by the gun itself charged only with powder, by placing it 

 close to the gates with its muzzle from them; the njonien- 

 tufo of recoil being generally sufficient to force such ob- 

 jects completely. 

 p/;'v?at, iiJ7- Ero.m the circumstance, that no English admiral or cora- 

 ckiVc fir^i':(i)" « npunder ever commences tiring till his ships are about to b^ 

 ■ "^ ^ grappled, 



i-.eibi.l of, a 



