124 Mr. C. A. Chant on the Variation of Potential along 
and a number of differences in the behaviour of the cathode 
and anode, besides the one mentioned above, stated. 
4. The behaviour of amalgams, as well as pure alkali 
metals, has been investigated, and the complete analogy 
between the behaviour of the arc in their vapours and that 
of the mercury-are shown. 
). Different ways have been found to cause an alternating 
current to pass through mercury vapour in form of an are. 
6. On the basis of this a theoretically almost perfect rectifier 
for conversion of alternating current into steady direct current 
was developed. 
In conclusion, I wish to acknowledge the great help I have 
obtained from Dr. Kruh, who assisted me in carrying out the 
work on the alternating current, and take pleasure in ex- 
pressing my thanks to Dr. C. P. Steinmetz and to Dr. W. 
R. Whitney, Director of this Laboratory, for their interest in 
this work and many valuable suggestions. 
Schenectady, N.Y., July 17th, 1903. 


XII. The Variation of Potential along the Transmitting 
Antenna in Wireless Telegraphy. By C. A. CHANT*. 
[Plates XII. & XIIL] 
I. Introduction. 
N a former paper + illustrations were given of the manner 
in which standing waves are formed on a free-ending wire 
when the electrical disturbance is produced by electrostatic 
induction from a Hertzian oscillator at the other end of the 
wire. The present communication contains a somewhat de- 
tailed account of an examination of the aerial wire used to 
radiate the waves in wireless telegraphy ; and, in a section at 
the end, a brief account of a continuation of the former 
experiments. 
The problem of the electrical oscillations about a free-ending 
wire has been treated from a rigid theoretical basis by 
Abraham {, who determined the electric and magnetic forces 
at any point in the field by directly integrating the Maxwellian 
equations. For the purposes of analysis the wire was con- 
sidered to have the form of a very elongated paraboloid of 
* Communicated by Prof. Trowbridge. 
+ C. A. Chant, ‘The Variation of Potential along a Wire Transmitting 
Electric Waves.” Am. Jour. Sci. xv. p. 54 (1903); Phil. Mag. ser. 6, 
y. p. 331 (1903). 
{ M. Abraham, Ann. der Physik, ii. p. 32 (1900). 
