NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2015 Apr 13, 09:06 -0700
Francis,
The sketch title is VP Impressions. VP is a clue to the place Venus Point for which latitude and longitude is known. Plug in the time of LAN for the day of the 1769 Venus transit at this location using USNO and see the coincidence of GHA for the Sun and Venus. Both bodies are passing the meridian at nearly the same time. This is perhaps the reason Capt. Samuel Wallis (HMS Dolphin) suggested Tahiti as an ideal place to observe the 1769 transit of Venus. The attached data should be enough info to determine Hs using an estimate for Capt. Cook's height of eye.
Greg Rudzinski
From: Francis Upchurch
Date: 2015 Apr 13, 02:01 -0700Greg, you clever but naughty rascal!
Like Dave, I spent hours burning the midnight oil and www, trying to find this "impressionistic" painting from the Endeavour trip (1769 a bit early for even the earliest impressionists!) Anyways great picture. You should publish it. How do you work out Hs and Hc from this? Perhaps from the positon of Venus/sun which I guess can be timed exactly from the early records?
Frank, I think you have made a major medical discovery named "sticky neuron syndrome"! I have it (serious case). Another glass of red wine, the only known cure, or is it the cause? Can't remember!
Francis
