E. L. Carney—Liffect of Vibrations upon Electro-magnets. 205 
case of the iron rod it will be noticed that the tertiary vibra- 
ions are greater than the secondary, while the reverse is true 
with the steel rod. 
The current was then broken and the amount of deflection 
noticed; and afterward a tertiary current obtained in the 
more than one tertiary being obtained, it was probably due to 
the feebleness of the first vibration. 
In all these experiments the tertiary currents were in the 
same direction as the secondary ones, differing in this respect 
from those of Table IL. 
The magnetizing helix in both cases was fifteen centimeters 
from the center of the rods. 
Tron rod. 
Current made. pred lira by Current broken. Figg rm by 
+ + ves st 
40 60-10-10 45 40-5 
47 50-5-10-5 50 45 
42 40-15 40 30 
15 20 10 30 
15 30 17 30 
ti $2 16 32 
Steel rod. 
db 
Current made. pride nase bY | Current broken. pags abi / 
-+- + a a 
20 10 25 10 
22 Qo7 15 
23 5-3 29 15 
20 10 20 "10 
Table III.—Here the magnetizing coil was placed on the 
rods instead of at right angles to them, as In the previous cases, 
oe the experiment was performed as described in Table 
was broken the tertiary current was greater than the secondary, 
while in Table II. the tertiary current was greater when the 
current was made. : : 
On the iron rod the magnetizing helix was distant forty cen- 
timeters from the center; on the steel rod twenty-two. 
