Roy Atwell

Doc (voice) (uncredited)

Professor Washburn

Arthur Sidney

Bearded Man on Ship (uncredited)

Salesman

Arthur Tirrey - Casting Director

Doc (voice) (archive footage)

Senator Sam H. Smiley

Professor Kockerthaler

Mr. Pippensigal

Vale

Jim Conwell

Dick Saunders

Jerry Sidon

Harkness Boyd

Marmaduke Grubb

Horace Kane

Winston Gates

Announcer