ME.  FAIEBAIEN  ON  THE  EESISTANCE  OF  TUBES  TO  COLLAPSE. 
395 
the  difference  from  the  result  in  the  Tables  being  2 lbs.  in  the  one  case  and  If  lb.  in 
the  other. 
The  following  results  on  10-inch  tubes  are  also  remarkably  consistent  with  the  above 
law. 
Table  IV.  Eesistance  of  10-inch  tubes. 
Mark. 
No. 
Diameter. 
inches. 
Length. 
inches. 
Thickness. 
inch. 
Pressure  of 
collapse, 
lbs.  per  sq.  in. 
Remarks. 
Q. 
16 
10 
50 
•043 
19 
R. 
17 
10 
30 
•043 
33 
Both  tubes  gave  way,  as  in  the  preceding  experiments,  with  a loud  report.  Com- 
paring them,  we  have  60  : 30 : : 33 : ^=19-8 ; and  by  experiment  (16.)  we  have  19  lbs. 
Equally  strong  evidence  in  confirmation  of  the  law  respecting  the  lengths,  will  be  found 
in  the  Table  of  12-inch  tubes.  The  increase  of  diameter,  without  any  change  in  the 
thickness  of  metal,  does  not  affect  it.  On  the  contrary,  this  principle  of  resistance,  in  the 
case  of  tubes  with  unyielding  ends  and  open  for  the  escape  of  the  contained  air,  holds 
true,  uniformly,  throughout  the  whole  of  the  experiments  on  4,  6,  8,  10,  and  12-inch 
tubes,  as  nearly  as  could  be  expected  when  due  allowance  is  made  for  variations  in  the 
rigidity  of  the  plates,  imperfections  in  the  workmanship,  and  difference  in  the  tension  of 
the  sides. 
Table  V.  Eesistance  of  12-inch  tubes. 
