|There are/were a number of methods, whether at sea or on land, by which the|
Chronometer Error may be found by means of astronomical observation. The Lunar Distance, of course, immediately comes to mind, but there are other methods available, including Equal Altitudes (solar or stellar), Longitude Time Sight, etc., should the Navigator be in a position to otherwise accurately establish his Longitude. It was quite common, before the days radio, for a vessel to check CE when passing a well charted headland or navigational aid by reference to which the Longitude might be accurately deduced; vessels frequently shaped their course so as to sight well charted Islands or other locations, which sighting afforded the opportunity to check their chronometers - Saint Helena, the Azores, the Canaries, etc., to name but a few. Surveyors and Navigators might also
ascertain CE, when in a place of know Longitude, i.e., in Port or elsewhere, by Equal Altitudes, both solar and stellar, at either upper or lower Meridian Transit, as well as by Time Sight. Lastly, there was also always the time ball or flag, whether in port or when passing a signal station manned by Lloyds, or other agency; the Port time ball usually dropped at a specific time each day, while the signal station would visually communicate a passing vessel on demand. You see, there was more than one way to skin a cat, most of which have been long forgotten.
--- On Wed, 5/6/09, James N Wilson <email@example.com> wrote:
From: James N Wilson <firstname.lastname@example.org>
Subject: [NavList 8159] Re: How Many Chronometers?
Date: Wednesday, May 6,
Navigation List archive: www.fer3.com/arc
To post, email NavList@fer3.com
To unsubscribe, email NavListemail@example.com
What is NavList?
You can also join by posting. Your first on-topic post automatically makes you a member.
Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.