74  Mr.  hutton  on  the  initial 
firmly  fixed  to  it,  the  one  next  the  upper  end,  and  the 
other  near  the  lower,  fo  as  itrongly  to  refill  the  endea- 
vours of  the  fhot  to  fplit  the  wood. 
The  whole  weight  of  the  pendulum,  thus  fitted  up, 
was  552  pounds ; its  whole  length,  from  the  middle  of 
the  axis  to  the  tape  at  the  bottom,  was  1 o r inches ; the 
diftance  to  the  center  of  gravity  was  78  inches;  and  the 
/ 
diftance  to  the  center  of  ofcdlation  was  88  inches  equal 
to  7 } feet,  which  was  exaftly  the  fame  as  that  of  the 
former  pendulum,  their  numbers  of  vibrations  being 
alike  in  the  fame  time. 
Inftead  of  fufpending  this  pendulum,  after  the  man- 
ner of  the  former,  by  the  ends  of  its  axis  in  grooves 
turned  to  fit  them,  they  were  only  placed  on  fiat,  level 
pieces  of  wood,  on  which  this  pendulum  vibrated  much 
freer  than  the  other  did;  but  a fmall  nail  was  driven 
into  the  fupporting  wood,  juft  behind  each  end  of  the 
axis,  to  prevent  the  ftroke  of  the  fhot  from  throwing  it 
off  the  ftand. 
To  this  pendulum  was  adapted  a better  machine  for 
the  tape  to  Aide  through  than  the  former  one  was,  the 
inconvenience  of  which  had  often  been  experienced  by 
its  catching  and  entangling  the  tape,  fo  as  to  interrupt  its 
free  motion,  and  once  indeed  to  break  it.  This  new  one, 
however,  is  at  once  very  fimple,  and  perfectly  free  from 
every 
