150 
NAL ORE 
[APRIL 9, 1914 
The Central Meteorological and Geophysical In- 
stitute of Chile has issued a volume containing hourly 
observations and means for Santiago for the year 
1g11, including all the principal meteorological 
elements, prepared under the direction of Dr. W. 
Knoche. This is the first time that such values have 
been published in extenso in Chile, and it is intended 
to continue them regularly for Santiago in future. 
There are several other stations in Chile, where hourly 
observations are available; the publication of some 
of these, or at least summaries from them, would be 
very valuable, but the large amount of work entailed 
thereby is said to be more than the limited staff is 
able at present to cope with. 
The nineteenth annual report of ‘‘ Meteorology in 
Mysore’’ for rg11 contains, as usual, daily and 
monthly results of observations for Bangalore and 
Mysore, and 8h, a.m. observations, with monthly 
means for Hassan and Chitaldrug. Synopses of the 
monthly and yearly results made at those observatories 
are carefully arranged as before, for the purpose of 
comparison, by Mr. Iyengar, in charge of the Mysore 
meteorological department. A useful table giving the 
means for the nineteen years 1893-1911 shows that 
the absolute maxima of temperature ranged from 
100:2° at Hassan (3149 ft.) to 103-0° at Chitaldrug 
(2405 ft.). The minima at the same stations were 
42-7° and 51-2° respectively. Yearly rainfall ranged 
from 25:0 in. (ninety-one days) at Chitaldrug, to 
35°8 in. (121 days) at Hassan. The mean relative 
humidity was about 60 per cent. at all stations; 
excessively low readings were observed occasionally. 
The Royal Magnetical and Meteorological Observa- 
tory of Batavia has published the results of rainfall 
observations in the Netherlands’ East Indies for 1911 
(part ii. of the thirty-third yearly series). The volume 
contains the monthly and yearly amounts at a. large 
number of stations, the number of rain-days, greatest 
amounts in twenty-four hours, averages for the period 
1879-1911, departures from those values in 1911, and 
other useful details. These data, in addition to their 
general scientific value, are of great importance locally, 
and it has been pointed out elsewhere by Dr. Van 
Bemmelen that rainfall is the ruling factor which 
determines the weather in the archipelago, because 
the remaining meteorological elements are almost con- 
stant. In Java the yearly amounts for 1911 varied 
from 23 in. at Sitoebondo (long. 114° E.) to 177 in. at 
Pelantoengan (long. 110° E.), and even more in the 
outside possessions. The greatest rainfall in one day 
was 10-2 in. at Padang (Sumatra) in November. The 
fullest information is given respecting the stations, 
but this volume contains no general discussion of the 
results. 
IMPROVEMENTS IN ‘LONG-DISTANCE 
TELEPHONY. 
HE subject of improvements in telephony is one 
in which the general public is very 
interested, and a large audience, including many 
experts, therefore followed with attention the e€Xposi- 
tions given by Dr. J. A. Fleming, F.R.S., at the Royal 
Institution on March 27, in which he described the 
inventions that of late years have enabled a great 
increase in the practicable distance of telephonic com- 
munication to be made, and also rendered possible the 
use of submarine telephone cables over distances not 
hitherto attainable. In his opening remarks, Dr. 
Fleming gave first a_ brief description of the con- 
struction of the modern telephone transmitter and 
receiver, and of the transformations and sources cf 
loss of energy in transmitting electrically articulate 
speech between two places. He stated that he would 
confine attention chiefly to the action of the line of 
NOy 23nO hon 4G. 
closely 
cable, neglecting the imperfections of the transmitter 
and receiver per se owing to limitations of time. 
An experiment was first shown with an instrument 
which projected upon the screen in the form of a line of 
light, the motion of the diaphragm of a telephone, 
when sounds musical or articulate where made near 
it The sound of an open organ pipe was thus seen 
to produce a smooth wavy or simple harmonic curve, 
whilst the less pure sound* of a harmonium reed or 
of the voice uttering a vowel sound produced a com- 
plex curve, and a spoken sentence an irregular wave 
line. 
The use of the oscillograph in recording. photo- 
graphically or visually the wave form of the electric 
current sent into a telephone was next explained, and 
photographs of various vowel and _ syllabic sounds 
shown. 
A few words of explanation were then given con- 
cerning Fourier’s theorem in virtue of which any 
irregular but single valued curve can be resolved into 
the sum of a number of simple harmonic curves of 
various amplitudes and phase differences having fre- 
quencies in the ratio of 1, 2, 3, etc. 
It was then explained that the action of the trans- 
mitter on the line was equivalent to the imposition of 
a complex electromotive force which in virtue of 
Fourier’s theorem could be regarded as the sum of 
a large number of simple harmonic electromotive 
forces of various amplitudes, wave-lengths, and phase 
differences. 
Every telephonic cable has four primary qualities, 
two conservative, viz., its inductance and capacity, in 
consequence of which it can store up kinetic and 
potential energy in the form of a magnetic or electro- 
static field. Also it has two dissipative qualities, viz., 
its conductor resistance and dielectric leakance, which 
convert a part of the energy given to it into heat. 
Hence an electromotive impulse given to the cable at 
one end is propagated along it as a wave. The cur- 
rent in the cable at each point is oscillatory, but the 
current is not, so to speak, at high tide simultaneously 
at all points in the cable, but successively, the maxi- 
mum value travelling along the cable with a certain 
speed. The mode of propagation of a wave along a 
string or wire was illustrated by various wave models. 
In the case of a wire or string of finite length the 
wave is reflected at the far end, and if the time taken 
by the wave to travel to and fro is equal to some 
exact multiple of the periodic time of the impulses, 
stationary waves are produced on the cord or wire. 
These effects, together with a demonstration of the 
laws of string vibration, were proved by the aid of 
Dr. Fleming’s vibrating string apparatus in which a 
light cotton cord has one end fixed to a slide rest 
and the other end twirled uniformly with an irrota- 
tional motion by an electric motor. 
The production of stationary electric waves on wires 
was also beautifully shown by the use of a long wire 
coiled into a helix on an ebonite rod. One end of this 
helix was connected to the earth and the other to a 
high-frequency oscillator. On adjusting the frequency 
of the oscillator, stationary electric waves of wave- 
length equal to some exact multiple or fraction of the 
length of the helix were produced and shown to exist 
by the brilliant glow of a neon vacuum tube held near 
the ventral segments and its non-glow when held near 
the nodes. 
Dr. Fleming then explained that in the case of a 
telephone wire the velocity with which the waves 
travel along it is greater the shorter the wave-length, 
and also that in virtue of the resistance and dielectric 
leakance, these waves attenuate in amplitude at a 
rate which is greater for short waves than for long 
ones. 
frequency currents the wave velocity is the same for 
In the case of the helix operated on by high- 
ee LLG EEA ~ aaa 
