A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Rafal O.
Date: 2019 Feb 12, 08:36 -0800
I have found thia post while searching throught the NavList archive. As I like such analog computers, slide rules, ... I decided to make my own version of this sunrise / sunset computer.
You can see assembled unit in the attached images. Let us check its accuracy: I want to know thr time of sunrise and sunset for November, 15th for 51N and 17E. Equation of time and declination are -15min and 19S, respectively. These values can be read on the back of the computer. Aligning 19S declination with 51N latitude gives me the following UTC times for 0E: 0730 and 1623. After adding EoT: 0715 and 1608. Correction for latitude is -0108 which corresponds to 0607 and 1500 UTC. These correspond to 0707 and 1600 local time. On timeanddate.com I get 0707 and 1603. Errors are 0 for sunrise (clearly very lucky) and -3 for sunset. Quite good for the first try, I think.