[Antipodal]

i    Hi      everyone, This is a bit of a long shot but Google has not provided an answer - and perhaps it will be clear why.  
I  have come across a   New Zealand newspaper article from 1911 which describes a demonstration  here  in Wellington  , our capital city , of a piece of apparatus called a "Phonofor " .  This equipment allowed voice transmission along a morse telegraph line of over 100 miles long apparently as clear as a bell with none of the buzzing which apparently characterised attempts at trying to send voice messages along a telegraph line usually dedicated to morse transmission. 
The reason I am interested is because this demonstration , to a small group of interested railway personel back in 1911 was conducted by my great grandfather who was at that time the second in charge electrical engineer for  the New Zealand Government  Railways. 
Another newspaper cutting describes him overseeing the installation of electric lighting in the Invercargill locomotive roundhouse, current being provided by a gas engine and generator installed nearby.
If anyone can throw any light on what the Phonofor was and /or how it worked I would be very grateful. The reason I have tried here on the Phorum is because New Zealand Railways did source much of its equipment from the United States, Baldwin locomotives being one such . Thanks everyone.