From my Internet browsing in the middle of the night. 1938 Popular Mechanics Magazine......
"....the invention of the counter seat that also serves as a scale......by consulting the dial customers can determine whether to order fattening foods..."
Can you even imagine the horror of this invention? Can you? So not only do YOU see how much you weigh as you dine, but so does the soda jerk (what a jerk) and your husband and friends? Are you kidding me? What could this have done for business? Could not have been good...I wonder if any were ever even used.
Reminds me a little of "The Big Yellow House" restaurant that was here in the OC when I was a kid. They weighed you (kids only) as you went in and as you left to determine the cost of your meal. Amazing that place is no longer around....oh the horror of it all.