176 BELL SYSTEM TECHNICAL JOURNAL 



There are various ways in which the combination circuit can be 

 set up and operated and it will take further experience before 

 the most satisfactory arrangement is determined upon. In order 

 to explain the operation generally, however, we will describe how the 

 circuit was actually set up during the tests. Take the case of a call 

 originating on the vessel; then the procedure is as illustrated in 

 Fig. 21, namely: 



1. When the ship comes within range she calls the land station by 

 telegraph on 600 meters, and informs the land station of her 

 message business. 



2. The land station then assigns a pair of telephone channels to 

 which both stations switch over and the circuit tested out for 

 talking. In case of important long distance land line connec- 

 tion, this test may involve circuit transmission measurements. 



3. The ship operator then passes to the land operator by voice (or 

 by tone modulation telegraph) the information as to the con- 

 nection desired. 



4. The land operator then tells the ship operator to stand by while 

 he switches to the wire circuit and passes the call to the telephone 

 central, who in the case of a local call is a local operator (actually, 

 for this case, she was the operator on the Cortlandt Official 

 Board of the American Telephone and Telegraph Company at 

 New York; or in the case of a long distance call is a toll operator. 



5. The land line connection is made in the usual way and the shore 

 station radio operator greets the land line subscribers. 



6. The shore station operator then joins together the land line and 

 the radio link thus connecting the land subscriber with the ship 

 operator, who proceeds to tell the subscriber that this is the 

 steamship so and so and that Mr. Blank wishes to talk with 

 him. While this is going on, the land operator is monitoring 

 on the circuit and makes such final adjustments of the amplifica- 

 tion as may be necessary. 



7. The ship operator then summons the ship subscriber and the 

 latter takes up the conversation. 



The handling of calls originated by the land line subscriber presents 

 a more difficult operating problem because of the uncertainty as to 

 the radio link — it not being known whether it can be established 

 and, if so, as to how long a wait will be involved in getting the con- 

 nection. During the tests, most of the calls originated in New York 



