Pneumatic Tubes

We old farts fondly remember those magical vacuum tube systems in department stores. The kindly sales lady filled out your purchase form, took your money, placed it in a space-age doohickey and whoosh it would zip away. 

I never thought much of where it zipped. All I knew was that your change would come whizzing back and off you'd go. 

For a kid, it was magic. Clearly, for the central operator, it was Frankenstein.