"You sound like you're in a tin can."

 ...via blog.modernmechanix.com

You can insure absolute privacy and secrecy with “SCHER’S IMPROVED TELEPHONE MUFFLER”

You need not leave our desk or go to a private booth to talk freely, and confidentially over the phone. This invention gives the equivalence of a telephone booth.

It is instantly attached and detached on the telephone transmitter. No complicated parts. Occupies 3-1/2 inches of space on the mouth piece of “phone” and is at your elbow when in need. It is unquestionably the most useful telephone accessory of today. Made of Aluminum, lasts a lifetime. Used by U. S. Dept. of Agriculture, First N’tl Bank, Guarantee Trust Co.. and thousands of others over the world. If dealers can’t supply you, we will forward one prepaid on receipt of $3.50.

AGENTS wanted in U. S. and foreign countries. Write for territory.

The Amalgamated Sales Corp., Mfrs., 1478 Broadway, Dept. C.S., New York City
Source: Popular Electricity And Modern Mechanics
Issue: Sep, 1914