68  Mr.  hutton  on  the  initial 
out,  becaufe  that  its  correction  was  fo  fmall  as  not  to 
make  a difference  of  above  a foot  or  two  at  moft  in  the 
velocity:  and  for  the  fame  reafon  this  correction  is 
neglected,  as  quite  unneceifary,  in  the  reft  of  the  experi- 
ments of  the  other  days  following. 
The  mean  velocity  of  the  fecond,  third,  fourth,  fifth, 
and  fixth  numbers  is  626,  and  of  the  feventli  and  eighth 
it  is  915;  that  is,  the  velocity  with  two  ounces  of  pow- 
der was  626  feet  per  fecond,  and  that  with  four  ounces 
was  915  feet ; and  thefe  two  velocities  are  in  the  ratio  of 
t to  1.46.  But  the  mean  weight  of  the  balls  in  the 
former  cafe  was  17}  ounces,  and  in  the  latter  it  was  17-i 
ounces;  and  the  ratio  of  the  quantities  of  powder  was 
that  of  1 to  2.  But  the  direct  fub-duplicate  ratio  of  the 
powder,  compounded  with  the  inverfe  fub-duplicate 
ratio  of  the  weights  of  the  fhot,  forms  the  ratio  of  1 to 
1.42,  which  is  nearly  equal  to  the  ratio  (1  to  1.46)  of 
the  velocities ; that  is,  in  this  inftance  the  velocities  are 
very  nearly  as  the  fquare  roots  of  the  quantities  of  pow- 
der diredlly,  and  the  fquare  roots  of  the  weights  of  the 
balls  inverfely.  The  powder  was  forced  up  with  only 
one  ftroke  of  the  rammer. 
The  fecond  courfe  was  performed  on  the  3d  of  June, 
1 7 7 5>  which  was  a clear,  dry  day,  but  windy.  Some  of 
the 
