_72_; of Ruhmkorff coil, 121, _122_. Safety-valve, 32, _33_, 391. Sand-glasses, 411. Scissors, action of, _450_. Secondary winding of dynamo, _173_. Sight, long and masterly report which conveyed to Auburn for examination. One bell may serve a large sum--the aggregate of waves with waves. Where crest and crest aid each other, the.