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[April* 
PROCEEDINGS OF SOCIETIES. 
Royal Society, February 13. — A paper by Mr. J. E. H. Gordon, 
“ On an Extension of the Phenomena discovered by Dr. Kerr, 
and described by him under the title of ‘ A New Relation between 
Electricity and Light,’ ” was read. In November, 1875, Dr. Kerr 
announced, in the “ Philosophical Magazine,” that he had disco- 
vered a new relation between electricity and light. He showed 
that when glass is subjected to an intense electrostatic stress 
that a strain is produced which causes the glass to aCt like a 
crystal upon polarised light. While the author was endeavouring, 
by means of the eleCtric light, to project the effeCt of Dr. Kerr’s 
experiment on a screen, the electrostatic stress was accidentally 
allowed to become strong enough to perforate the glass. Imme- 
diately before perforation there occurred the following effects : — 
First appeared a patch of orange-brown light, about 6 or 7 inches 
diameter. This at once resolved itself into a series of four or 
five irregular concentric rings, dark and orange-brown, the outer 
one perhaps being 14 inches diameter. In about two seconds 
more these vanished, and were succeeded by a huge black cross 
about 3 feet across, seen on a faintly luminous ground. The 
arms of the cross were along the planes of polarisation, and 
therefore were at 45 0 to the line of stress. The glass then gave 
way, and all the phenomena disappeared except the extreme ends 
of the cross, and the discharge through the hole, where the glass 
had been perforated, was alone seen. 
February 27. — “ Studies in Acoustics. I. On the Synthetic 
Examination of Vowel Sounds.” By William Henry Preece and 
Augustus Stroh. In their investigation the authors assumed 
that vowels are compounded of a prime sound and certain upper 
partials. Since each partial can be considered as a simple har- 
monic curve, if we assume the pitch of a prime to be constant, 
then it would be possible, by means of a machine, to represent 
and vary each partial in phase and in amplitude. For this pur- 
pose an instrument was constructed, which the authors call “the 
synthetic curve machine,” in which a number of toothed wheels 
are mounted on steel pins or axes rigidly fixed on a board, so 
that they will revolve together, and the numbers of their teeth 
are so calculated that during one revolution of the wheel A, B 
will make two, C three, D four, E five, F six, G seven, H eight 
revolutions, and so on. Besides assuming the pitch to be con- 
stant, the authors assumed that each octave of the partial, to 
