NavList:

Tom H, you wrote:
"Many delicious details about navigation" etc.

Unfortunately those details are sometimes massively ingnorant bullshit. In the specific section you quoted from the edition available on archive.org, we see an amateurish account of the history of navigation. He had read other historically inaccurate stories about navigation and crafted his own colorful account. The exquisite "colors" of his writing eventually shine through, but you really have to ignore his sidebar ramblings. He doesn't know what he's talking about.

For example, in the section you included in your post, Murchie writes:
"Newton's new method of lunar distances was too laborious and complicated for anyone but a magician."

This is the traditional mid-20th-century-dumb-guy account of lunars. The method of lunar distances or "lunars", as it was commonly known among practical navigators, was not Newton's, it was not too laborious or complicated, and it was widely practiced by ordinary, lightly-educated navigators. Even in the context of the highly simplistic discussion of Cook's navigation here, Murchie's analysis is wrong since Cook and the teams of navigators on his vessels actively employed lunars for longitude on a regular basis.

In another spot in the book (searchable in the text version at archive.org), he suggests, anachronistically, that Portuguese navigators before Columbus were dependent on lunar distance tables:
"not even as well provided in respect to navigation as Prince Henry's ships coasting down West Africa way forty years earlier with their astronomers, their bronze peloruses, their astrolabes decorated with the zodiac, their Regiment of the Pole Star, their pilot books and tables of lunar distances."

Wow. He's just throwing around terminology. Using jargon as a spice in prose can be effective. It can draw the reader in with the mystery of an undiscovered world of science and ideas. But it's pointless if the author is merely throwing around words. And that's the case here. And if he's wildly wrong in this section, can you trust him on matters of content elsewhere? 

But we don't have to trust his content on subjects outside his understanding. This ain't no textbook! We can ditch the idea that we'll learn anything beyond the limits of this practical man from his book. He wants to babble about history, but he doesn't know history. He wants to teach science, but he doesn't know science. Fine. Now that we know that about him, we can let him spin the lyrical yarns of his life.

For example, at the beginning of the book, setting his tone, Murchie writes of the wind at high altitude in an old aircraft (a four-engine C-54, a military version of the DC-4, of the type known most famously from the Berlin Airlift):
"It [the wind] sprang full-bom from the Plexiglas nose and exploded upon the duralumin skin, sprawling backward over the humps of the astrodome and the engines, tearing itself cruelly on each protruding edge of cowling, each pitot and spar. It was the invisible substance of which the sky is made — not just air, not just wind, but a stuff which is part of the insoluble consciousness of flight. 'Why is that octant in your hand?'
Because I am the navigator. I hold the needle that will pierce the cloud. I sing the song of the sky. "

Hallelujah!! That's some juicy exposition right there, and he's doing what every author should do. He's describing his own experiences, his impressions. his inner life, in his own words. He's also letting us know right here that he is an egocentric artist at heart, and I mean that in a good way. In every film, in every concert, every play, the best performers even in the tiniest roles universally fantasize and envision themselves, materialize themselves, as the focus of the whole show, the center of the whole damn production! And Murchie clearly materialized his role as navigator as the aircrew's central player. All hail the navigator! 

Frank Reed