54 Scientific Intelligence. 
the one to charge, the other to dischar condenser. Those 
produced in the second spiral illuminate the Geissler tube very 
brilliantly. 
are formed, but presenting before the last inversion all the charac- 
ters produced by a Ruhmkorff coil. The same effects are pro- 
duced by altering the distance of the spirals or of the plates of 
the condenser. These condensers show that the phenomenon in 
question bears no relation to the lateral discharge, characterized 
especially by the constancy of the direction of the current it pro- 
uces.— Comptes Rendus, \xxix, 1071. Bi 0.8 
3. Effect of Flame on an Electric Spark.—Mr. 8. J. MixtER 
eighth of an inch. Inserting this between the two terminals of 
the balls could be separated. The same increase was not obtained 
simply inserting a conductor between the two terminals, a ball 
an inch in diameter only lengthening the spark about an inch. 
E. C. P. 
4. Laws of Tuning Forks.—M. Mercapimr has determined ex- 
perimentally the effect of a change in the dimensions of a tuning 
on its number of vibrations, A style is attached to the en 
of the prong and draws a sinuous line on a revolving cylinder 
covered with lampblack. Another style attached to an electro- 
magnet registers the beats of a clock giving seconds, The vibra- 
tion of the fork is maintained electrically. By the thickness of 
prong is meant its dimension parallel to the vibrations, by 1ts 
readth, the perpendicular direction. A fork having a breadth of 
35°3 mms, gave 144-7 vibrations. Reducing its breadth to 30°9 
and 24°8 it still gave 144-7 and 144-9 vibrations. Hence the num- 
ber of vibrations is independent of the breadth. A similar meas- 
