BANKING: The Snorkel

In Denver one day last week, a motorist pulled up to the curb in front of the Colorado State Bank. He rolled down his window, and began talking to what looked like a grey steel mailbox at the curb. It was no mailbox, but a "snorkel" (so called after the German submarine air intake) for curbstone banking.

Bank Teller Robert Gibson, an ex-B-29 pilot, was at the lower end of the snorkel, twelve feet down in a cashier's cage beneath the sidewalk. By means of a periscope and a loudspeaker running up through the steel box, he could see and...