A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2016 Aug 19, 19:14 -0700
In NZ we have an amazing historical resource called the "Appendices To The Journal of the House of Representatives" or AJHR for short. In the 19th century a Freedom Of Information Act was not needed because everything dealt with by the Government, including technical reports, was published in the Appendices. Today the Appendices are available online at a site called AtoJs Online.
I went to AtoJs Online and typed in the keyword time. I immediately came up with
which shows that in 1876 the longitude difference between Wellington and Sydney was measured by telegraph signals. It is reasonable to assume that the longitude difference between Sydney and London had been similarly determined so by 1876 the longitude of Wellington was (probably) accurately known.
This is an example of quick use being made of new technology. The first telegraph cable between London and Sydney opened in 1872. NZ's first external cable (to Sydney) opened in 1876.
In the report the longitude differences are given in units of time. According to Google Earth the longitude difference between Wellington and Sydney is approximately 24°, which is about 1 hr 36min in time.