The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1867-03-07
APPLIED SCIENCE.

''sIEema AND DANCING" rLANE.

NnStftublOu, HAS DboA contributed DY n11nSel
70 the last number of the Philosophical Maga
sine. ND.
The sounding of a hydrogen flame wher
inclosed within glass tube was, I believe
6rst noticed by DR.. Higgins. in 1777. The
subject has been since investigated by Chladni,
De La Rive, Faraday, Wheatstone Rijke,
Sondhauss, and Kundt. The action,of unid6-
nant sounds on flames inolosed in tubes has
been investigated by Count Schaffgotsch and
myself The jumping of naked fish -tai
Same, in response to musical sounds, was fI4t
noticed by Professor Leconte at q musical partV
in the United States. He made the important
observation that the flame did not Jump until
ii was near haring. That the discovery was
not further followed up by this learned inves-
tigator was probably due to too great stretch
Of courtesy on his part towards myself Last
year. while preparing the experiments for one
of my 'Juvenile Lectures, - my late assistant
Mr. Barrett observed the effect Independently;
and he afterwards succeeded in illustrating It
by some very striking experiments. With a
view to the present DISCOURSE and also TO the
requirements of forthcoming work on sound,
the subject of sounding and sensitive flames
has been recently submitted to examination in
the laboratory of the Royal Institution. The
principal results of the inquiry are embodied
in the following abstract;-
"Pass a steadily burning candle rapidly
through the air, you obtain an indented band
of light, while an almost musical sound heard
at the same time announces the rhythmic
character of the motion. If, on the other hand.
you blow against a candle fame the huttering
noise produced indicates a rhythmic action,
When a iuttering of the air is produced at the
embouchure of an organ pipe, the resonance of
the pipe reintOrces that particular pulse of the
futter whose period Of vibration comedies
with its own, and raises it to a musical sound
When a gas flame is introduced into an open
tube of suitable length and width, the current
of air passing over the flame produces such a
futter, which the resonance of the tube exalts
to a musical sound. Introducing gas flameint
this tin tube three feet long, we obtain a rich
musical note; introducing it into a tube six feet
long, we obtain a note an octave deeper
the pitch of the note depending on the length
of the tube. Introducing the flame into this
third tube, which is fifteen feet long, the
sound assumes extraordinary intensity. The
vibrations which produce it are sufficiently
powerful to shake the pillars, floors, seats,
gallery, and the FIVE or six hundred people
who occupy the seats and gallery. The flame
is sometimes extinguished by its own violence,
and ends its peal by an explosion as loud as a
pistol shot. The roar of flame in chimney
is of this character; it is a rude attempt at
music. By varying the size of the flame, these
tubes may be caused to emit their harmonic
sounds. Passing from large pipes to small
ones, we obtain a series of musical notes
which rise in pitch as the tube diminishes in
length. This fame, surrounded by a tube l75
inches long, vibrates 45S times in a second;
while that contained in this tube, l0S inches
hong, vibrates III times in a second. Owing
to the intense heat of the sounding column.
These numbers are greater than those CORES
ponding to organ pipes of the same length
sounding in air. The vibrations of the flame
consist of a series of partial extinctions and
reviVals of the flame. The singing flame ap-
pears continuous; but if the head be moved
to and fro, or if an opera glass directed to the
name be caused to move to and fro, or if, after
the method Of WheatstOne, the flame be
regarded in a mirror which is caused to rotate
the images due to the revivals of the flame are
separated from each other, and form a chain
OF flames of great beauty. With longer tube
and larger flame, by means of a concave mirror,
l can project this chain of flames upon a
screen. first clasp my hand round the end
OF the tube so as to prevent the current of air
which causes the futter from passing over the
flame; the image of the flame is now steady
upon the screen before you. l move the mir
ror, and you have this continuous luminous
band. withdraw my hand, the current of air
passes over the flame, and instantly the band
breaks up into chain of images. position
san be chosen in the tube at which the flame
bursts spontaneously into song. A position
may also be chosen where the flame is silent
but at which, if it could only be started, it
would continue to sound. 1t is possible to
start such silent flame by pitch-pipe, by the
siren, or by the human voice. 1t is also posi-
BILE to cause one flame to effect the musical
ignition of another The sound which starts
the flame must be nearly in unison with its
own. Both flames must be so near unison as
to produce distinct beats. A flame may be
employed to detect sonorous vibrations in air
Thus, in front of this resonant case which
supports large and powerful tuning fork,
move this bright gas flame to and fro. A
continuous band of light is produced, slightly
lndented through the friction of the air. The
1ork is now sounded and instantly this band
breaks up into series of distinct images of
the flame. Approaching the same flame to-
wards either end of one of our tin tubes with
the sounding flames within it, and causing il
10 move to and fro, the sonorous vibrations
also enect the breaking up of the band of light
into cnaln OF images. In this glass tlrbe, four
Teen lncnes long, a flame is sounding. bring
The nat hame Of fsh-tail burner over the tube
the Droad slPe OF the flame being at right angles
10 the axis OF the tube The fsh-tail flame in
stantly ernlts musical note of the same mitch
as that OF the singing flame but of different
quality. It's sound is, in fact that of n ,nor,,
brane, the part of which it here plavs. Acainst
broad bat's-wing flame l allow a sheet of air
issuing from thin Slit to impinge. A must
cal note is the consequence. The note can be
produced by air or by carbonic acid but Il 10
produced with greater force and purity NV
oxygen. The pitch of the note depends on
the distance of the slit from the flame
Before you burns a bright candle flame. I
may shout, clap my hands, sound this
whistle, strike this anvil with a hammer
or explode a mixture of oxygen and hydro