Fig. 47.
The Condenser is made up of 70 sheets of tinfoil each about 4 inches by 7-1/2, and 80 sheets of clean white paper 5 by 8 inches placed alternately, and saturated with paraffin wax. The tinfoil sheets are laid so that about 1/2 inch projects out of the paper sheets at each end, the alternate sheets coming out at the same end, and the projecting pieces being bent together gives the effect of a pair of tinfoil sheets insulated from each other, aggregating the sum of all the small ones.
Fig. 48.
The coil can now be attached to the base by means of screws passing through the lid into the coil ends. If a vibrating contact breaker be desired, reference to Fig. 44 will show method of connection. Fig. 47 shows details of a contact breaker of similar design. R is hammer head of soft iron, S a spring about thickness of clock spring and 3/8 inch wide or more. B is contact point, both spring and adjustment screw A being fitted with platinum contacts. C is a check nut, to hold A from turning. I is an adjustment to tighten or loosen spring S, by means of a lug which it carries on its shaft. It is well insulated from pillar carrying A, by the hard rubber bushing, I.
The condenser is laid in the box under the coil and attached as in Fig. 44; that is, one set of sheets to the contact pillar, and the other set to the adjustment screw.
For gas-lighting work, it is generally preferable to use a contact or strap key (Fig. 48), instead of a vibrator. The key can be mounted on coil base, in which case the condenser will be attached in same manner as for the vibrator.