W. B. saint on Sonorous Flames. 9 
paced of the tube. A oftcente regular movement may then be 
ven by the hand. If now we adjust the flame in the tube so 
nb it will not begin to sing for some time after the vibration 
has commenced or until the tube is farther lowered, we observe 
at “<— merely the continuous band of light due to the perma- 
nence of the visual impression, but as soon as the g com- 
mences this band becomes waved or odes at top and vith a 
= r velocity divides —_ nearly separate columns of flame 
obscure spaces betwee 
w The effect is however fa more ss when the flame ts made 
fo revolue at a uniform rate in the tube. In this case so long as it 
remains silent it presents the appearance of a hollow cyinies 
or short tube of whitish light, but the moment that the singing 
begins the cylinder assumes a toothed form on the top resem- 
bling a brilliant crown and divides itself into a number of narrow 
luminous columns separated by bands nearly or quite deprived of 
ease the velocity of rotation, a less number of vibrations 
or Pega in this case case corresponding to one revolution A 2 “es 
2 renee the effect visible at a distance it is of course n eS 
a large tube and flame. It is ton ke beautifully % 
distinct eure the tube is some six feet long by one and a a 
inches in diameter and the flame three-fourths of fan inch in ~~ 
height. “The mechanism employed to give rotation to the jet Cs 
consists of a grooved wheel con- 4 
nected by a band with a small 
pulley (fig. 2). Into the latter the 
supply-pipe enters from below b 
a smooth gas-tight joint eo 
allows the pulley freely to revolve. 
The jet-pipe secured to the middle 
of the wu one Sapsraan eegpar go sha 5 
yr, and rising 
ameter. ; 
To secure the pipe more firmly in its upright position it is made 
to pass near its base through a narrow gallows of brass in which 
SECOND SERIES, Vor. XXVI No. 76.—JULY, 1868. 
2 
