Chemistry and Physics. 485 
the arrangement of the three flames is particularly useful, because 
the constant images of the upper and lower flames render the 
slightest variations of the rst flame very perceptible, If U 
an= 00] is sung to the note ¢ in the apparatus, the funda- 
mental tone is but weakl y aiecesid by the octave; if we then 
arrange the apparatus so that the waves of ¢ interfere, ev + trace. 
of this octave disappears ; while on interference of the fi amen- ~ 
tal note two narrow flames of almost equal height take the place 
of each broad one, which represents the octave which exists now 
almost alone. If we sing O to the same note, where the octave is 
stronger than with U, we ean make the same experiments, but 
here the tone 3 appears on sine of the octave, the broad 
flame of the fundamental note changing into three points succes- 
sively i erie roe in altitude. If the waves of the octave inter- 
fere we get a group of five peaks of flame which indicate the tones 
1, 3, 5. If we suppress the fundamental tone and with it the tones 
3, 5. etc., we get a simple series of flames caused alone by the 
,a 
especially in more composite groups of flames pertaining to th 
ower notes, ill therefore remark, that on lengthening one 
tube of the apparatus we often sudde very considerable 
the point of interference of the lower octave or sae ot a higher 
overtone of the note which is separated in this man 
Instead of shies branchmg tube, in which the pound was intro- 
duced in the preceding experiment, we can use two separate tubes 
* exactly squat a length and shape, each of which consisting of 
three pieces united a * in a telescope, so that the two open ends 
may be turned i y direction without ne = length or 
ing t 
nt g 
and for the ae of Zoch, I et prov are the ches with 
two stop-cocks by which they may be filled and shone oe 
; é erie ai 
si 
f the tubes with india rubber rings to prevent the 
as from esca : at these poi 
Of peril t ag appara on. do for direct observation of the 
- different phenomena of interference with the ear, and for wc 
ing the experiments of Mach, Quincke and others. For this pur 
