O.Henry is describing the office of a stock broker.
He mentions ticker tape.

I wonder how many members have ever seen ticker tape.
It was a very long perhaps inch wide roll, and had holes
punched into it electrically by signals sent over telephone,
I guess. A busy broker's office receiving stock market
quotations by it, would accumulate many yards of it during
a day. I remember seeing newreels of Lindberg's parade up Fifth Avenue being festooned with miles of ticker tape.