NavList:

Continuing the media attention following the death of Mike Sadler at age 103...

Martin W. sent a message quoting the obituary in The Economist last week. The Econ is great prose at its best, and their obituaries are often fascinating essays. The final line of this essay about Sadler's life is poetry, and I encourage you to read it: here. I can't post the whole obituary here because it's protected by copyright, but here are a few choice bits...

The article says of Sadler:
"Navigation required both geometry and maths, but at school he was poor at both."

...which, of course, is not a problem because the tools of celestial navigation and other forms of scientific navigation have been designed from the earliest days to be manageable by people who are not especially skilled at math! It takes a degree of comfort and confidence in math... but beyond basic arithmetic, the rest is largely un-necessary.

One of the worst developments that I personally have encountered in recent decades is the rise of the pompous blowhard who loves to pronounce "spherical trigonometry" and is convinced by his own incompetence in math that celestial navigation must begin with a rigorous lesson in the solution of spherical triangles. Nope. That's a problem, not a solution. If the math is difficult, you're probably doing it wrong! :)

Continuing in the article...
"he was persuaded in a bar in Cairo to join the Long Range Desert Group (LRDG), which provided transport for the SAS and could train him to tell by celestial signs exactly where his position was. It seemed to him a magic art, and the desert like being on the sea in a way. Reading the stars, you could go in any direction, a great sort of freedom. When the war was over he became a keen sailor."

" He used the sun-compass invented by Ralph Bagnold, founder of the LRDG, which showed the sun-shadow in relation to the compass points but had to be constantly adjusted. In any case, they did not travel by day if they could help it. This meant he was up half the night finding suitable stars, taking star-readings with his theodolite, carefully recording them and then correcting the record the next day. Despite his efforts and the group’s successes, he thought he was only a passable navigator."

That makes good sense (theodolite sights at night). Of course travel by night in the desert is a great idea if you can see well enough to make sure you don't drive into rocks, but navigation by night is an excellent idea, too, and in many ways makes this land-based navigation more like air navigation though at low speeds. With a theodolite you can get fixes all night long, at least in principle --no horizon needed. I would guess no more than two fixes were required in a typical night. I gather one did not normally need to worry about overcast either. Deserts do often have the advantage of clear skies (no rain... that's why they are deserts!).

The article adds:
"In daytime dead-reckoning navigation he refused to go by hunches, but carefully plotted out velocity over distance to measure the convoy’s progress towards its target. "

I would love to know if we have that from interviews with Sadler. Did he state bluntly that he "refused to go by hunches"? If so, that's my impression of a good navigator. It's why we need scientific navigation in the first place. Hunches are just a bad idea. On the other hand, memoirs can be tricky evidence. Maybe he followed his hunches every day, and maybe they worked. Conceivably he re-wrote his own story in his head because he didn't like to see himself as following hunches. After so many decades, there's probably no way to know for sure...

Frank Reed
Clockwork Mapping / ReedNavigation.com
Conanicut Island USA