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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Slocum's lunars
From: Frank Reed CT
Date: 2003 Dec 13, 19:14 EST
From: Frank Reed CT
Date: 2003 Dec 13, 19:14 EST
Jan Kalivod wrote:
" to verify the longitude obtained by DR, if used at all. (Frank's interesting reference to whalers' logbooks proves it.)"
I couldn't quite figure out what you meant here. The reference to whalers' logbooks proves what?
While I'm here, I can elaborate a bit on one of those logs. The first mate's (?) log from the maiden voyage of Mystic Seaport's whaleship, the Charles W. Morgan, has miraculously survived. The ship left New Bedford in September of 1841 and returned home when the barrels were full of oil in January of 1845. This was a typical length for a whaling voyage in mid-century. She spent most of this time in the Pacific and made port every few months in Peru or California. The vessel also stopped a number of times in the Galapagos to pick up the ingredients for turtle soup. In those 39 long months, there is one "longitude by lunars". The rest are "by chrono". But there are a couple of terse references to officers "working lunars" which make it clear that the ship's navigators were aware that they needed to keep in practice. This level of usage is about what you would expect: c.1840 is often cited as the time period when lunars had become decidedly secondary in navigation.
For whaleships by the mid 19th century, the easiest way to check the chronometer was to ask the captain of a passing ship who was fewer days from port. The seas were busy in the 19th century. At the end of the century, Slocum met several ships eager to tell him the longitude.
It's a bit like me and wristwatches... I never wore or carried a watch because I could always ask someone who did! I made a point of it. Of course, now, my all-purpose multi-function cell phone/camera/internet access device/photo album/calculator/game console/flashlight/GPS receiver is also... a watch. Drat.
Frank E. Reed
[X] Mystic, Connecticut
[ ] Chicago, Illinois
" to verify the longitude obtained by DR, if used at all. (Frank's interesting reference to whalers' logbooks proves it.)"
I couldn't quite figure out what you meant here. The reference to whalers' logbooks proves what?
While I'm here, I can elaborate a bit on one of those logs. The first mate's (?) log from the maiden voyage of Mystic Seaport's whaleship, the Charles W. Morgan, has miraculously survived. The ship left New Bedford in September of 1841 and returned home when the barrels were full of oil in January of 1845. This was a typical length for a whaling voyage in mid-century. She spent most of this time in the Pacific and made port every few months in Peru or California. The vessel also stopped a number of times in the Galapagos to pick up the ingredients for turtle soup. In those 39 long months, there is one "longitude by lunars". The rest are "by chrono". But there are a couple of terse references to officers "working lunars" which make it clear that the ship's navigators were aware that they needed to keep in practice. This level of usage is about what you would expect: c.1840 is often cited as the time period when lunars had become decidedly secondary in navigation.
For whaleships by the mid 19th century, the easiest way to check the chronometer was to ask the captain of a passing ship who was fewer days from port. The seas were busy in the 19th century. At the end of the century, Slocum met several ships eager to tell him the longitude.
It's a bit like me and wristwatches... I never wore or carried a watch because I could always ask someone who did! I made a point of it. Of course, now, my all-purpose multi-function cell phone/camera/internet access device/photo album/calculator/game console/flashlight/GPS receiver is also... a watch. Drat.
Frank E. Reed
[X] Mystic, Connecticut
[ ] Chicago, Illinois
