261. Condenser, marine, 71, _72_; of Ruhmkorff coil, 121, _122_. Safety-valve, 32, _33_, 391. Sand-glasses, 411. Scissors, action of, _450_. Secondary winding of induction coil, see p. 122 Chapter V. ELECTRICAL APPARATUS. What is the _pull_ exerted through the operation of the little girl if.