The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1874-02-18
Professor Tynasirs Recent Experiments
on Fog sigasls-A Warning 70 Mar

liners.
Professor Tyndall has recently been con-
Quoting q series of experiments to test the
acoustic character of fog signals. His expert
ments have been undertaken in connection
with the labors and under the co-supervision
of the Trinity House Committee, and the re-
ported results are of great interest.
In lecture delivered before the Royal In
stitution on the 18th ult he announced some
of his conclusions, arrived at after observa-
tons extending over q period of six months
and during many vicissitudes of wind and
weather. AS far as we can gather from brief
account of his lecture in the London Nautical
Magazine it appears that the distances at which
fog signals are audible on different days vary
in o most remarkable manner. He is reported
as saying that if the sound of q gun can be
heard on fine, calm day at q distance of ten
miles, the experiments show that there is no
reason why on another apparently similar day
the sound should be heard at only three or
four miles. On the 10th and Doth of May
it seemed to be demonstrated to
certainty that the sound of gun
could be distinguished further than that of
trumpet And yet on succeeding days the
trumpet was audible at several miles distance,
and the gun inaudible. Again, on June Is.
with the wind favorable, no sounds were per-
ceived at six miles, while the day following,
with wind opposed, they were clearly heard
nine miles. Once, during thick haze, which
hid the land from view and limited the visible
RI hale
were distinguishable over twelve miles dis
lance, while on some clear days they were in
audible at very much shorter distances.
The uncertainty and variability in the
aerial transmission of signal sounds, thus
brought to light are of immediate and vital
Importance to the mariner, and demand an ex-
haustive investigation, as well as thorough re-
vision of ideas now prevailing on this subject.
Professor Tyndalrs labors would seem to show
that our fog signals are not to be relied on for
distance exceeding three miles, and, perhaps,
under some aerial conditions, less
The homogeneity of the air strata and their
relatively tranquil condition, it is known,
greatly affect the intensity of sound, and per-
NIT the sonorous waves to be propagated
without losing their amplitude by reflection.
If there is an irregular commixture of light
and dense air then the sound waves are re-
fected back from the interposing walls of the
denser media. This principle, which has
been clearly brought out by Professor
Lockyer, was strikin:Ny verified on the Sd of
July, when the air seemed to be singularly
lacking in homogeneity, and Professor Tyndall
OBSERVATION-DISCLOSURES it was a clear, calm
and sunny day-that nothing at all was audible
at three miles. 1t was proved on going to the
place on shore where the signals were sound
ing that echoes of fifteen seconds duration
came back from the air space in front, show
ing what had become of intransmissible sound,
which was lost to the listeners only three
miles of. In this singular instance the dense
air had been opaque to the sound, and the
sonorous wave breaking against it was arrested
as wave of the sea breaking on rock
Enough is revealed by these initiatory in
vestigatons to show our present ignorance of
the practical transmission of fog signals and
the consequent jeopardy of navigation until
the precise distance to which they are audible
can be determined. Cannot our own govern
ment assist in this investigation
The ENGLISH ELECTIONS. Mr. Gladstone
has rendered his resignation to Queen Victoria
and Mr.. Disraeli has been summoned to form
Ministry. The defeat of The liberal Minis
try has been complete In England the tories
have swept the boroughs in which
the liberal strength was supposed to
rest and the defeat of the Glad
stone government in Ireland has been still
more marked. Notwithstanding the short
time allowed them for preparation the home
rulers have carried ffty-eight seats. If they
act together in the new Parliament they will
hold balance Of power. Dsrael will come
into power with working majority, but on
many questions where party lines will not
be very severely drawn the position of the
government will not be very secure. It is
probable that the advent of the conservatives
will materially aid the progress of liberalism
in England, although it appears on the sur
face severe check to the reform movement
inaugurated by Mr.. Gladstone. Our special
cable dispatches announce the elevation to
the peerage of two members of the late Minis
try and three other prominent supporters of
Mr.. Gladstone.
PUT MONEY IN Thy PURsE.-Men who de-
vote themselves to any religious or benevolent
service are supposed to do it in spirit of self
sacrifice and under the stimulus of an exalted
idea of moral duty, which the mass of men
admire, even if they cannot initiate; and the
consciousness that they are performing duty
more or less sacred has always been recognized
as the true reward of such men, both by the
world and themselves. But that notion evil