ACOUSTIC TELEGRAPHY. 
45 
3,000 subscribers, at Philadelphia 600, at Cincinnati 600, 
and an ever-increasing number in New York ; the total number 
of subscribers to telephonic offices in America exceeding 
70,000. 
The telephonic service at New York is managed as follows :—• 
If we enter the principal hall of the Merchants’ Telephone 
Fig. 16. 
Exchange at 198, Broadway, we see a number of switchmen (see 
Eig. 14) employed in establishing communication between the 
subscribers. At one place a switchman is listening to a sub¬ 
scriber who has called (Fig. 15), at another the employe is 
removing a call-signal (Fig. 17). The subscriber has, at his 
place in the city, his office telephone (Fig. 16), such being placed 
in a great many places of business. This form is very con¬ 
venient, for the mouth-piece on the left side may bespoken into 
