New-York tribune., 1901-07-28
FOG SIGNAL EXPERIMENTS.
IMPORTANT RESEARCHES BY BRITISH Exi
PERTS.
IERTS.
From The London Times,

PEElS.
From The London Times.
Twenty-Five years ago the Trinity House Cor
poration with the advice and assistance Oh fio-
fessor I'vndall carried out some interesting eX-
periments at the South Foreland. near Dover,
in regard to the use Of sound Tor slgnalins ~
the mariner, TO warn him of his proximity 10
danger at times when fog or other KINDS OF lhlch
weather prevented his seeing the land or sea
marks by day or the guiding or warning lights
at night The scientific aspect of the question
IS fully given in the late editions OF "Iyndall on
Sound" and the practical results obtained nave
been shown in the large increase In the huthoer
OF fog signal stations around our coasts ana the
adoption OF certain instruments for producing
sounds which had not previously been employed
In this country.
with the lapse OF time and the growth OF
the coast fog signal system, new knowledge mas
been gained and new developments have taken
place, and 1t has become necessary TO test oy
practical and comparative experiments the
value Of certain theoretical improvements which
have from time to time been introduced, ana 10
endeavor to determine some moot points which
have arisen in connection with the general ques-
tIon Accordiuulv a special committee of the
Elder Brethren Of Trinity House was appointed,
the deputy master being chairman, with whom
were associated Lord RayleiEh, scientific ad-
wiser. and the engineers Of the three lighthouse
boards. to consider the present position or the
subject and Ia carry out such experiments as
they might regard necessary. st. GATHERINGS
Point, in the Isle OF wight, was selected Tor the
trials Here there is a lighthouse with a power
full electric arc light produced by steam power
which also serves for compressinS air into re-
d
At this statl,n the committee has now been
carrying its work during the last two or
three weeks, observations being made at sea
each day by members of the committee on board
the Trinity yacht Irene. One important question
upon which the committee has been engaged is
that OF the relative merits Of sirens as sound
producing Instruments compared with reeds.
1t does not seem probable that the vibrations
set up by means of reed possibly be
powerful as those produced by means of a siren,
and il will be interesting to learn the results of
the committees observations on this point.
The form Of the trumpet sound protector is
also receiving considerable attention, Lord Ray
leigh himself having certain theoretical views
on the point which he desires to have PRACTICAL
ly tested. The relative merits of notes Of diff
ferent pitch, in regard to their Capability OF
penetrating the atmosphere under unfaVOrable
conditions is another branch of the inquiry
which is being followed up by the committee.
and some useful information this point may
result from the experiments. The question Of
the most effective and economical utilization OF
power for operating sound signals is also receiv-
ing much consideration. 1t is obvious that there
must be limitations in respect of the size of in
StrumcntS and the development Of power for
working them. Other matters for inquiry and
experimental test are questions connected with
the best site for land sound signal, regard be-
ing had TO the nature of the coast line and the
neiShbOrinS physical features also how a sea
area which is to he guarded can be most eff
ciently covered by the sound of the signal. The
various forms of siren and reed vibrators have
come INTO the trials, with the view of deciding
which form, size, and description of vibrator is
best adapted for producing the sounds: and
questions respecting pressure, air consumed and
length of blast also being dealt with. The
Investigations ought to yield some very interest
ing results which it is hoped will in due course
be published