20 min. color Wolff(GE) Jh-sh-col-ad $1.00. ... Theory of ionization applied to gas- filled tubes; control of current in circuits employing gas-fUled tubes; use of the gas diode as a rectifier; action of the grid in ... Friction gears and toothed gears; law of gearing; positive driving, involute profiles; pressure angle; cycloid ... Steps in the canning of foods that are governed by principles of bacteriology and sterilization; factors of temperature control, timing and ... (Printing) PROBLEM CHILDREN.
|Title||:||Catalog of Educational Motion Pictures|