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Re: Time sight primer
From: Brad Morris
Date: 2019 Sep 26, 20:21 -0400
From: Brad Morris
Date: 2019 Sep 26, 20:21 -0400
Chris
Prior to longitude by lunars, there was longitude by account (dead reckoning).
Nevil Maskelyne promulgated lunars. Longitude by Lunar. This was used for some decades to follow, being supplanted eventually by chronometers.
With the advent of chronometers, longitude by chronometer became an accepted practice. Somewhere around the 1830's if memory serves me properly. This was strictly a longitude line to be combined with your latitude line.
Time Sight navigation existed well into the 1900's. It provided a single position, latitude and longitude.
So no, longitude by chronometer did not replace time sight. What did replace it was St.Hilaire (Sumner lines), the cocked hat and the endless debate over where, relative to that cocked hat, you are. Instead of latitude and longitude lines, you get LOPs.
Brad
On Thu, Sep 26, 2019, 8:03 PM Chris Mitchell <NoReply_Mitchell@fer3.com> wrote:
Frank,
Thanks for clairification. It was the equation of time that was throwing me off. Would it be safe to say that this method of finding longitude and local apparent time was replaced with by more modern logititude by chronometer method and UTC?
Chris
