Auto Vacuum Freezer Ice Cream, anyone?

I've stumbled on an old copy of the Boston Cooking School Cook Book from 1923, by none other than Fannie Merritt Farmer of that revered classic. Besides the interesting content, which I'll be writing about later I'm sure, the book is a treasure trove of old food ads. I'm going to be posting a few of them in the coming days. (I've got a bit of a computer issue at the moment so no long posts from me for a few more days.)

This one, for example, is an ad for a contraption to make ice cream. I wonder what it's all about. Something perhaps related to using liquid nitrogen which, strangely enough, is hardly new at all.

I've tried to find more information about this particular contraption on the web, but so far my search has turned up nothing. Has anyone heard of this company? Do you know what this Vacuum Freezer thing is exactly?