Dating old australian photographs
Pole routes with a single wire carried by an insulator at the top of the pole, and possibly a few more in a staggered formation on the sides, as shown in figure 1, are usually telegraph routes, but the same construction was sometimes used for telephone routes if only a few wires were needed.
Pole routes with crossarms and numerous wires are always for telephone services.
A line to Brisbane followed soon after and services were progressively extended to country towns and suburban centres.
As a single wire could serve a dozen offices on an "omnibus" or "party" line, most routes had only one to three wires.
It took some time before the best combination of the two techniques was established. to a number of distribution points from which the lines continued to the subscriber on pole routes.The construction shown in figure 1 was nearly always used.A separate telegraph network was built by the Railways Department for signalling and operational needs and the two services often shared a common route.The consequence of all this activity was that from 1883 to 1900 nearly every street in the commercial area of Sydney had a pole route, the appearance of which changed frequently as wires were added and in due course were replaced by cables. (ref 3'4'5) This is a distinctive feature which can be seen on many photographs.Potentially, therefore, these poles form a valuable dating guide for the period by allowing a series of photographs of the same street to be placed in chronological order. It became the backbone of the network with pole routes branching off at every cross street.