Summary: Two young boys are told about the birds and animals native to Ohio.

Credits: Author, Robert Welchans.

© Cinecraft Productions, Inc.; 8Jan49; MP3827.

OHM'S LAW. De Forest's Training, Inc., c1948. 100 ft., b&w, 16mm. (Radio Electronics. Reel lesson 1)

Summary: Illustrates the mathematical relationship of pressure, current, and resistance in an electric circuit.

Credits: Producer, Paul Satterfield.

© De Forest's Training, Inc.; 1Oct48; MP3814.

OIL. Calumet Refining Co. 16mm.

Credits: Narrator, John Weigel.

© Albert J. Smith & Lyle W. Munson; title, descr., & 9 prints. 11Jul40; MU10330.