An important contribution of F.I. Balyukevich to the history of telephony was the invention in 1892 of a telephone-railway signaling system for transmission over telegraph wire.
A railway engineer and assistant chief of traffic at the Zakavkazskaya Railway, Balyukevich appreciated the merits of both telephony and telegraphy as developed by E.I. Gvozdev. He engaged in their implementation at the railways and sought to put them to wider use. He strongly criticized the conservatives, who feared equipping railways with new communications technology.
In the system proposed by Balyukevich, a fonopor was used. The device was adapted for telephony over telegraph wire. Instead of inductor calling, a vibrator with an induction coil and a receiver was used as well as an electromagnet with an anchor, making a sound like a horn. Balyukevich first applied differential transformers for telephone messages over telegraph wire.