A Telephone Attachment Which Performs the Services of a Watch Dog
RUPERT H. GREENLAW, of New York, has invented a meter attachment which is a mechanical watch-dog for your
telephone. It consists of a small case containing a locking and registering mechanism, a clamp which fastens it to the telephone standard, and a rod which
engages with the telephone receiver. By removing the receiver the rod is forced in and out of the interior of the meter. It is impossible to replace the receiver upon the hook until the call has been registered.