77 
Velocities  of  Cannon  Balls , 8cc. 
Veloc.  with 
2 ounces. 
612 
622 
605 
3)1839 
The  means,  613 
Veloc.  with 
Veloc.  with 
4 ounces. 
8 ounces. 
879 
1164 
871 
* *54 
'870 
1x69 
3)2620 
3)3487 
873 
1162 
The  uniformity  of  thefe  velocities  is  very  linking,  and 
the  means  with  two,  four,  and  eight  ounces  of  powder 
are  613,  873,  and  1162,  which  are  in  the  ratio  of  1, 
1.424,  and  1.9;  thefe  numbers  are  nearly  in  the  ratio 
of  the  fquare  roots  of  the  quantities  (2,  4,  and  8)  of 
powder,  the  numbers  in  this  latter  ratio  being  1,  1.4 14, 
and  2,  where  the  fmall  difference  lies  chiefly  in  the  laft 
number.  A fmall  part  of  this  defect  in  the  greateft  velo- 
city is  to  be  attributed  to  the  mean  weight  of  the  balls 
ufed  with  it  being  greater  than  in  the  others;  for  the 
mean  weight  of  the  balls  ufed  with  eight  ounces  of  pow- 
der is  2 8j  ounces,  while  that  with  the  two  and  four 
ounces  is  only  28};  the  reciprocal  fub-duplicate  ratio  of 
thefe  is  that  of  1 to  1.006,  in  which  proportion,  in- 
creafing  1.9  the  number  for  the  greater  velocity,  it  be- 
comes 1. 9 1,  which  flill  falls  fhort  of  a by  .09,  which  is 
about  the  -'Td  part  too  fmall  for  the  fub-duplicate  ratio  of 
the' 
