B. S. HYEE MEASUBEMENTS OF ELECTEIC WAVES. 
61 
were encountered. Tn the first place, it was discovered that, with 
the same resonators, there were variations in nodal distances too 
great to be accounted for by errors of observation. The node 
nearest the free end was always found at the same distance — 
practically the length of the resonator, but further along the wire they 
were always some longer, but quite variable in this excess. More per- 
plexing still was the fact that the nodes were sometimes sharp and easily 
located, while at other times they were indistinct, and occasionally could 
not be located at all. One who has not repeated these experiments of 
Hertz can scarcely realize the difficulties encountered in this character 
of work. They are well, described by a writer in Nature , who says: “It is 
heartrending work at first. A bright spark now and then arouses hope, 
and long periods of darkness crush it again. The knobs of the generator 
require repolishing; the spark gap of the detector gets closed up; dust 
destroys all working; and not without much patience can the art be at- 
tained of making sure of getting sparks when the conditions are favorable, 
though it is easy enough not to get sparks when the conditions are un- 
favorable. Before making any measurements, all this practice must be 
gone through. It is hard enough, with the success of others before us 
to encourage us, w r ith their advice to lead us, with a clear knowledge of 
what is expected to guide us. How. much credit, then, is due Hertz, who 
groped his way to these wonderful experiments from step to step, without 
the success of others to encourage him, without the advice of others to 
lead him, without any certainty as to what was to be expected to guide 
him. Patiently, carefully, through many by-paths, with constant watch- 
fulness, and checking every advance by repeated and varied experiments 
Hertz worked up to the grand simplicity of the fundamental experiment 
in electricity that is engaging our attention.” 
After many attempts, Hertz failed to obtain anything very satisfactory 
concerning the velocity of waves in wires. I had discovered enough to 
know that Sarasin and De La Rive had fallen into serious error. 
I therefore determined to take up the subject of waves in wires. My 
results during the first three months given to the work were so discrepant 
that for a whole year I gave up all attempts to find any method in the 
mad affair. But from time to time I have returned to the subject. While 
very little has been accomplished, yet I have discovered certain facts, 
which, so far as I am aware, have not been pointed out by any other ob- 
server. 
Attention is first directed to diagram Ho. 1, in which the numbered 
horizontal lines represent different lengths of wire in which nodes have 
been located by means of three different resonators of 500 c.m. each. 
The first, or Ho. 1, was made of 24 wire, Ho. 2 of heavy wire, and Ho. 3 
