822 
MR. H. TOMLINSON ON THE INFLUENCE OF STRESS AND 
removed from A and four more transferred from A to B,'* and so on, until at length 
all the lead cylinders had been removed from A and all the brass cylinders transferred 
from A to the boxes B, B. The next experiments show the results obtained by 
treating steel and copper wires in this manner. 
Experiment VIII. 
Unannealed piano steel, 0 - 0824 centim. in diameter and 602 centims. in length. 
Mean vibration-period, 21’2825 seconds. The temperature ranged from 6° C. to 7° C. 
Load on the wire iu kilos. 
Logarithmic decrement due 
to internal fr ction. 
4-635 
•0003633 
8-635 
•0003381 
12-635 
•0003479 
16-635 
•0003658 
20-635 
•0003547 
Experiment IX. 
Annealed copper wire, 0T622 centim. in diameter and 602 centims. in length. Mean 
vibration-period, 7'340 seconds. The temperature ranged from 13° C. to 20° C. 
Load on the wire 
in kilos. 
Logarithmic 
decrement due to 
internal friction. 
4635 
•0002653 
8-635 
•0002239 
12-635 
•0002610 
16-635 
•0002616 
20-635 
•0002991 
The variations, which occur in the values of the logarithmic decrements for different 
loads, are to be attributed to differences in the rate at which the temperature varied 
on different days. Had a greater number of observations been made with each of the 
loads on different days, the mean values of the logarithmic decrements would have 
varied still less. We may say, then, that for comparatively large loads the internal 
friction is independent of the load, whether the wire be annealed or hard-drawn. 
We will now turn to consider the effect of comparatively light loading on the 
internal friction. 
* The figure shows the arrangements of the cylinders after this last operation. 
