Though the subtitle is "The Medium Irons", when talking to the boys after they've found Georgie, Bobby Jones tells them the best way to start in golf is "to get a mashie like this or mid-iron and putter and start knocking the ball around" until you get the feel of the club. (A "mid-iron" equals a modern 2 iron.) Jones never refers to a "medium iron", though that is what the mashie is. In Jones' time, clubs were named rather than numbered as they are in the modern era; the mashie is equivalent to today's 5-iron. [The club used in How I Play Golf, by Bobby Jones No. 4: 'the Mashie Niblick' (1931) is equivalent to a 7-iron.]
Vitaphone production reel #4796.