AvGUST 25, 1899. ] 
than 100,000 are lamps would become a 
single year’s production in this country 
alone. Faraday, when he made his re- 
searches npon the induction of electric cur- 
rents from magnetism, could not have had 
any idea of the enormous practical work in 
which the principles he dealt with as facts 
of pure science would find embodiment. 
When he wound upon the closed iron ring 
the two coils of wire which enabled him to 
discover the facts of mutual induction he 
had begun, without any suspicion of the 
fact, the experimental work which gave to 
science and to practice the modern trans- 
former, now built of capacities ranging up 
to 2,500 H. P. each, and for potentials of 
40,000 to 60,000 volts. 
These examples, and many others which 
might be given, should convince even the 
most arrogantly practical man of the high 
value of scientific research, not alone as 
adding to the sum-total of knowledge and 
for the admirable training it gives, but be- 
cause it cannot fail to have an ultimate 
practical effect. Discoveries which at first 
seem to have no useful nor practical out- 
come are often the very ones which under- 
lie development of the greatest importance 
in the arts and industries. 
The work of Hertz upon electric waves was 
tothe physicist a grand experimental demon- 
stration, tending to prove the truth of the 
electromagnetic theory of light, and subse- 
quent progress was profoundly influenced by 
it, though no practical use followed at once. 
The physicist to-day may see in the wire- 
less telegraph only an extension of Hertz’s 
original work, for he need not consider the 
commercial or economic outcome. He may, 
however, recognize the fact that in the 
wireless telegraph, as developed by Marconi, 
practice calls for a broader theoretical view. 
Certain elements of construction and adjust- 
ment of apparatus,at first used and regarded 
as essential from a theoretical standpoint, 
have already been laid aside. The radiator, 
SCIENCE. 
239 
with its large polished brass spheres and 
special spark gap, has been found of no 
more effect than the simple pair of small 
balls ordinarily constituting the terminals 
for high potential discharges. It has been 
found that the transmitting and receiving 
apparatus do not require to be attuned, and 
that the receiving coherer is not the true 
recipient of the electric wave or disturbance 
in the ether. 
These later developments are, in fact, de- 
partures, more or less wide, from the prin- 
ciples underlying the Hertz demonstration. 
A vertical wire is charged to a high poten- 
tial and discharges to earth over a spark 
gap. During the discharge the wire be- 
comes a radiator of electromagnetic pulses 
or waves, regardless of the spark radiation. 
The receiving vertical wire is likewise alone 
relied upon to absorb the energy. Being in 
the path of the electromagnetic wave con- 
veyed in the ether from the transmitting 
wire, it becomes the seat of electromotive 
forces which break down the coherer. This, 
in substance, may be considered as a series 
of small or microscopic spark gaps which 
can be crossed by the comparatively low 
potentials developed in the receiving wire. 
We are thus taught to recognize the fact 
that the refinements in methods and ap- 
paratus needed for a delicate physical 
demonstration as of the Hertz waves 
in this instance may often be laid aside 
in practical application, where the end 
to be achieved is different. The sudden 
discharge of the Marconi transmitting 
wire may possibly give rise to a series of 
oscillations or high-frequency alternating 
waves in the wire, but since the first half of 
the first wave at each discharge will have 
the greatest amplitude it is doubtful if 
those which follow in the short train have 
any decided effect upon the receiver. Ac- 
cording to this view the fact of the dis- 
charge being oscillatory may, indeed, have 
no essential relation to the work done, but 
