HOUSE TELEPHONE INSTALLATIONS. 125 



o[ replacing the receiver on its hook when the conversation is over releases the press button, and the line 

 is clear for receiving the next call. 



The &quot; central switchboard &quot; system differs from the &quot; intercommunication &quot; system by the fact 

 that an operator is needed to connect the instruments through which conversation is required, and to 

 disconnect them when the conversation is over, leaving them free to be used for other connections. It 

 is obvious that the efficient working of such a system depends upon an operator being constantly in 

 attendance ; but the switchboard is so simple that there is no reason why every servant in the house should 

 not lie taught to manipulate it. It is necessary, however, to make such rules that the switchboard shall 

 never be left unattended, and probably the best results are obtained when one servant is stationed 

 permanently at the switchboard. This would only be possible, of course, in a very large establishment. 



There are certain classes of communications that can very conveniently be left to the servant 

 operating the switchboard to transmit to their final destination. &quot; King up the garage, and tell the 

 chauffeur to bring the car round in ten minutes.&quot; Tell the gardener I wisli to see him in the orchid-house 

 in hall-an-hour,&quot; and so on. In this sense the presence of an operator saves time ; but the efficiency 

 ol the: system as a whole will largely depend on the operator at the switchboard, and in making comparisons 

 between the initial costs of the &quot; intercommunication &quot; and &quot; switchboard &quot; systems the wages of tin- 

 operator required iu the latter case should not be- forgotten. In the case of the &quot; intercommunication 

 system it is necessary to run a wire from every instrument to. every other instrument on the system. This 

 is done in practice by making up a cable with the same number of wires as there are instruments phis one 

 extra pair, which is used by all the instruments for ringing up, and also as a return path tor the telephone 

 current. It will be seen, therefore., that if this cable has to be run from the house to some outlying building 

 the cost may be greatly increased. The cable must then either be tarried overhead on insulators or. 

 what is more costly, be armoured and protected to make it suitable tor burying in the ground. ( (insider 

 a typical instance of a country house compactly built and titled up with an &quot; intercommunication &quot; 

 system for seventeen instruments. The cost of the installation would be about sixty pounds complete. 

 Now, supposing that one of these instruments was required at the lodge three hundred yards away, 

 another at the stables one hundred yards away, and a third at the game-keeper s cottage four hundred 

 yards away, leaving fourteen instruments in the house itself. The cable necessary tor connecting these 

 instruments into the system would be eight hundred yards in length and contain nineteen wires. Kven 

 if this were run overhead it would probably not cost less than one hundred and twenty pounds. It would 

 obviously be better in a case like this to connect the outlying instruments to one special instrument in 

 the house, situated in some centra! position, like the entrance hall, and to restrict the &quot; intercom 

 munication &quot; system to the house itself. 



A single pair of wires eight hundred yards long run on insulators overhead could be put up for about 

 ten pounds, provided that the insulators could be fixed to trees or house walls and no poles were needed. 

 So that, by using one special instrument in the house and connecting the outlying instruments to it, 

 great saving in initial cost would be effected. In the case of a &quot; central switchboard &quot; system these out 

 lying instruments would be connected to the switchboard in just the same way as the others, and no special 

 arrangements would be needed. If the same compactly-built house weie titled up with the same number 

 of telephones arranged on the &quot; central switchboard &quot; system, the cost, including the switchboard, would 

 be about forty-five pounds. If the outbuildings were situated some distance oil. as in the previous 

 example, the sum ot ten pounds already mentioned would have to be included lor overhead wires. In 

 a smaller establishment than the foregoing an &quot; intercommunication &quot; system tor six instruments only 

 has been fitted at a cost of thirty-seven pounds. 



In the smaller country house where extensive telephonic communication is not required, it may 

 be found convenient to instal a &amp;gt;rnall system of telephones directly connected with each other. Supposing, 

 for instance, that it is required to communicate between the dining-room ami kitchen. A telephone 

 in each of these rooms, with a pair of wires connecting them together, and the necessary electric batteries 

 for ringing and speaking, are all that is required If in addition to this it were desired to speak from the 

 bedroom of the mistress of the house to the kitchen, a telephone with a pair of wires connected to the kitchen 

 telephone could be fixed. It would then be possible to speak to the kitchen from either the dining-room 

 or bedroom, but it would not be possible to speak from the bedroom to the dining-room. This system 

 is very inexpensive. There are. indeed, instruments on the market costing only seven shillings and sixpence 

 each which can be used, and if there are electric bells in the house the same battery and wires will also serve 

 for the telephones. It should be noted, however, that if the bells and telephones are in frequent use there 

 is danger of the electric battery running down after a short time, in which case both bells and telephone 

 will cease to work. Good results can be, and have been, obtained from these telephones, probably 

 in those cases where someone in the house with an interest in electrical matters has looked to the battery 

 from time to time, or possibly in cases where the bells and telephones are not in constant use. Never 

 theless, it is usual for telephone contractors to recommend a more expensive instrument and a separate 

 system of electric batteries and wires. 



