A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2023 Mar 16, 08:05 -0700
Ed Popko, you wrote:
"It has been a while since I took Frank’s 19th C Celestial Navigation course, so I thought I would try to decode it."
Yes, it has been a while since you attended that workshop, hasn't it?! Just so everyone knows, the workshop, formerly known as "Celestial Navigation: 19th Century Methods" was renamed as "Celestial Navigation in the Age of Sail" about eight years ago. There will be sessions of this class later in the Spring. Here's a description at ReedNavigation.com.
"Most of the calculations were straight forward traditional practice."
Yes. Absolutely. And you know that it's "straight-forward traditional practice" because this is one of the key points that I get into in my workshop. Another key point is that it's not about the math. These navigators weren't sitting around, as modern navigation math-fans tend to do, contemplating secants and cosecants and spherical trigonometry. They knew how to work the problems, and they did the work. Navigation is not math --no more so than working a calculator is a branch of electronics.
"But two things struck me as odd. First, the Morgan was still hunting whales as late as 1897. In this log book example, they were just south of the Yellow Sea. Whaling was no longer a profitable business by the late 1800s. Why were they still out there?"
This specific voyage netted over $20,000 back on the docks in San Francisco when they returned to port at the end of the season (*). The evidence right in front of you is a huge clue. That navigation notebook would not exist if this was an unprofitable industry. The Charles W. Morgan was a commercial vessel. They didn't sail for fun. They sailed because they made money. They were hunting whales because it was, in fact, profitable in that old, beat-up whaling ship in 1897 (and for nearly a quarter century after that, too). We also discuss all of this in my "Age of Sail" workshop. The class I run is not just about the mechanics of a mathematical procedure. It's about the methodology of navigation more generally, the history of whaling, and the lives and story of that crew on this voyage in 1897 and others before and after.
"Second, the final longitude position from the calculations is not the one from February 20th, but the AVERAGE of the longitude positions from the 19th and 20th.. Was averaging two different day’s longitude a common practice? If you were recording the ship's position, say at 12:00 each day, I would think you would average that day's a.m and p.m. sites instead."
Sorry, but that's just wrong. You're making multiple assumptions about the numbers you're looking at based on scant evidence. No, they did not "average" the longitudes on those two dates. And No, that was not "common practice". Yes, the reported/recorded longitude is probably distinct from the longitude as calculated from the 9am/3pm Sun observation. Why? It's not complicated. More importantly, the work is not labeled for our understanding. Those navigators writing in that "scrap paper" notebook were not keeping notes for later navigation enthusiasts. Their work is not organized for us, in 2023. It was organized for their purposes, in 1897. You can try to puzzle out the work. The math bits are not difficult. The implications for navigation practice are far less obvious but also considerably more interesting.
Clockwork Mapping / ReedNavigation.com
Conanicut Island USA
* $22,600 on the docks for whale oil and whalebone (baleen) back in port. Let's call it $850,000 in modern money. Figure half to the owners. That leaves $425,000. Expenses during the voyage? Very low. Maybe $2000. Pay the captain $100,000. That leaves about $18,000 (2023 dollar equivalent) on average for each of the rest of the crew. Plus you get an 11-month cruise of the Pacific Ocean as a bonus. Nobody was getting rich, but the voyage was profitable.