Here's a strange little device from an ad in the June 15, 1939 Ypsilanti Daily Press. Can you divine what it might be?
The item, as friend J. K. correctly guessed, is a vacuum brew coffee maker. He also sent a link to a modern-day version (only $209!) The one in the link uses a spirit lamp, neato. Here's a video of how one works. The vacuum brewer above uses electricity. It is one of the myriad electric doodads that the Detroit Edison Company trotted out early in local municipal electrification days, which began roughly three decades before this 1939 ad. They just wanted to make your life more convenient!
The ad below is for a public cooking class with a new electric roaster at the Masonic Temple (Riverside Arts Center) led by "well known home economist" Lillian Merson. The glass coffeemaker was one of the three door prizes for this event, the others being one of the roasters and a "toaster tray set."
Roaster cooking is true electric cooking--cool, clean, fast, healthful, convenient--and it costs only about 2 cents an hour!