Hello Mr D: Here's a picture of an old book that I found by Cecil.H.Bullivant, date 1910. It has a chapter touting: "ventriloquism in one month".
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From Mr. D: A few pages of vent instruction with the promise you'll be one in one month. Not bad! I used to begin my one hour ventriloquist workshops promising attendees when they left the session at the end of the hour they would know how to be a ventriloquist. But I never promised how skilled they would be - you and I both know to become truly skilled you would need at least two or three hours - maybe as much as a month! (Or, perhaps, a lifetime.)