392      Tensile  Overstrain  and  Recovery  of  Aluminium,  etc. 
specimen  which  needed  considerable  hammering  to  remove  it 
from  the  wedge  grips  *,  it  was  suspected  that  vibration  had  a 
similar  effect  to  that  of  further  overstraining.  This  proved  to 
be  the  case,  as  is  obvious  from  Table  XV.  and  fig.  10,  the  curves 
A,  B,  C,  and  D  of  which  are  from  the  figures  in  columns 
3,  5,  7,  and  9  of  the  table.  The  difference  between  curves  B 
and  C  shows  the  effect  produced  by  vigorously  tapping  the 
specimen,  endwise  and  transversely,  with  a  hand  hammer. 
Table  XIV. — Specimen  Xo.  2  (Aluminium-Bronze). 
1st  Loading. 
Nov.  9, 1905. 
2nd  Loading. 
20  minutes  after 
3rd  Loading. 
1  hour  after 
4th  Loading, 
5  days  after 
Time 
Load 
overstrain. 
overstrain. 
overstrain. 
m 
Minutes. 
in 
Tons. 
i 
1 
Eeading. 
Diff. 
Reading. 
Diff. 
Reading. 
Diff. 
Reading.    Diff. 
0 
0 
200 
200 
200 
200     !     ... 
1 
1 
259 
59 
262 
62 
262 
62 
262     '     62 
2 
2 
321 
62 
329 
67 
331 
69 
325     1     63 
3 
3 
387(?) 
66(?) 
397 
66 
400 
69 
391         66 
4 
4 
448 
61 
468 
71 
470 
70 
458     J     67 
5 
5 
516 
68 
538 
70 
540 
70 
525     1     68 
6 
6 
581 
65 
609 
71 
611 
71 
593         68 
7 
7 
650 
69 
681 
72 
682 
71 
661         68 
8 
8 
718 
68 
755 
74 
754 
72 
731     1     70 
9 
9 
787 
69 
830 
75 
828 
74 
800     -     69 
10 
10 
858 
71 
905 
75 
901 
73 
871     j    71 
12 
38 
Table  XV. — Specimen  Xo. 
3  (Al 
uminium-Bronze). 
1st  Loading. 
2nd  Loading. 
3rd  Loading. 
4th  Loading. 
Nov.  16.  1905. 
15  minutes  after 
After  vibration, 
Nov.  22, 
1905, 
Time 
Load 
After  heating  to 
overstrain. 
and  30  minutes 
after  3  minutes 
in 
in 
99°  C. 
after  overstrain. 
at99c 
5C. 
Minutes. 
Tons. 
Reading.    Diff. 
Reading. 
Diff. 
Reading. 
Diff. 
i 
Reading. 
Diff. 
0 
0 
200    ;     ... 
200 
200 
200     1 
1 
2 
326     i     126 
330 
130 
340 
140 
326 
126 
2 
4 
465     |     139 
471 
141 
481 
14] 
462     ! 
136 
3 
6 
605 
140 
615 
144 
627 
146 
600     ! 
138 
4 
8 
747 
142 
761 
146 
776 
149 
741     | 
141 
5 
10 
895 
148 
911 
150 
928 
152 
888 
147 
7 
1 
38 
| 
i 
J 
*  In  obtaining  results,  shown  in  Table  XIV.,  the  specimen  was  left 
untouched  in  the  machine  between  successive  tests. 
