Page:Popular Science Monthly Volume 89.djvu/720

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Protecting the Telephone Operator

How the loud-speaking telephone elimi- nates danger from high-tension currents

���Th'^itiis 1' prcnlucts the exact tones of the sp. ,iki i \ i u lut v, tli mayulKd volumj and clearness, so that a whisper would be distinctly audible under ordinary conditions

��ELMCTRIC traction and power com- panies usually have their telephone lines on the same poles with high- tension fecHJerandtransmi tier-conductors. Asa result, telcphoneusi'rsnKU'heexpost'd to danger. The high-tension lini's may cross or touch teK-jihone lines, or the in- duced current in the telephone liiii's, due to their being parallel to the high-tension line, may lie sufliciently great to place the telef)hone operator in imminent danger.

I'"or proN'iding the recpiired protection under the al(o\e conditions, the loud- speaking tele[)Iione has been in\'ented. The person using the telephone does not (ome in aclu.d contact with it.

The apparatus illuslr.ited rejiroduces

��the voice as spoken into the transmitter with a volume somewhat greater than the s[)eaker's and with perfect clear- ness. If under ordinar\- contlitions a conversation in a rot)m fifteen feet sepiare can he imderstood, the speaker would not raisi' his Noice above the usual l>ilch. In operating the ajiparalus the conversational tone is reproduced with about the same volume and clear- ness. The speaker's natural voice is said to he easier to recognize than in the usual t\pc of ti'lephone. of lifting the receiver oil the hook, tin- method adopted with the ordinarN' idrphiMU'. the opi'r.ilor presses a lever with his foot to call "cinlr.d."


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