It is useful only in proportion to the number of other telephones it reaches.

AND EVERY TELEPHONE ANYWHERE ADDS VALUE TO EVERY OTHER TELEPHONE ON THE SAME SYSTEM OF WIRES.

That, in a sentence, is the keynote of equitable rates.
Many a telephone, for the general good, must be put where it does not earn its own living.

At any time some sudden emergency may arise that will make it for the moment priceless.

Especially since the advent of the automobile, there is no nook or corner from which it may not be supremely necessary, now and then, to send a message.