60 A. G. Bell—Ezxploring for an imbedded bullet. 
pies the position A B (fig. 30). We know then that the bullet 
is in that plane. Now incline the ring in some other direction 
and explore again. Let the position of maximum sound be now 
D. We know then that the bullet is somewhere on the 
straight line formed by the intersection of the planes A B and 
C It is only necessary then to make a third observation 
with the apparatus so inclined that the plane of the ring cuts ~ 
this straight line, for instance, the position E F. The point of 
intersection of the three planes G is then the exact point occu- 
pied by the bullet. 
I shall conclude this paper by the description of an experi- 
ment made in Newport, R. I., a few days ago. The results are 
so unprecedented in my experience that I feel they cannot be 
received as implicitly reliable until the experiments have been 
repeated and verified. 
amet es 
I had arranged upon a table three coils (as shown in fig. 31). 
The Jarge flat primary coil A was connected with a battery of 
four Bunsen elements and an interrupter, as shown, and the 
two small secondaries of fine wire, B C, were connected with a 
telephone. 
The secondary B was moved about on the primary A until 
a position of silence was obtained. Upon bringing a leaden 
bullet near C the balance was disturbed and a distinct sound 
produced from the telephone. There is nothing very strange 
about this when we know that the distance between A and C 
was only 15 centimeters, so that C was well within the field of 
induction of A; bat what did seem extraordinary was that the 
approach of the large steel blade of a penknife to the coil C 
produced no effect! The iron diaphragm of a hand telephone 
