192. Directions. (A) Charge the condenser by means of the electrophorus; then hang the carbon so that it can swing between the upper conductor and E C placed as shown.
193. The Electric Chime. The charging and discharging of the carbon being rapid, it acts like a chime as it taps against the tins.
EXPERIMENT 90. To ascertain the location of the charge in the condenser.
Apparatus. The condenser, consisting of flat box, F B (Nos. 40, 41); ebonite sheet, E S (No. 27); insulating table, I T ([Exp. 64]); (when charging, arrange as in [Fig. 52].); the electrophorus; hairpin discharger, H P D (No. 48).
194. Directions. (A) Charge the condenser with 15 or 20 good sparks from E C.
(B) Lift I T away from E S by its insulating handle, and set it upon the table. (It may be necessary to hold E S down.)
(C) Lift E S directly up and away from F B. (Lift by 2 corners; do not scrape E S along on F B; do not allow E S to touch your clothing.)
(D) Replace E S and then I T by its handle quickly, making the condenser complete again.
(E) With H P D see if the condenser still holds a charge. Touch F B first ([Exp. 86]).
195. Discussion. As the conductors were completely discharged, being left for a few moments upon the table, it is evident that the opposite electrifications must reside in and upon the dielectric. The conductors allow an even and rapid discharge from all parts of the dielectric at the same time. The dielectric is considerably strained when a condenser is heavily charged. This strain, caused by the attraction of the opposite electrifications, may be great enough to break or puncture the dielectric.