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 Three chronometers? Or "a pair?" 
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Post Three chronometers? Or "a pair?"
In Michael, Brother of Jerry, a justifiably obscure and extremely bad (trust me on this) novel by Jack London, he mentions that it was the practice to sail with three chronometers, so that if one of them failed to keep time it was possible to tell which of the three it was.

I mentioned this in an article in the USENET Risks forum, as a centuries-old appreciation of redundancy.

An old friend of mine who saw the article emailed me wondering whether Jack London was correct:
Quote:
And your note on Jack London and three chronometers. Do you know Patrick O'Brian's books? 20 novels of the Royal Navy in the Napoleonic Wars. I'm just in the middle of re-reading the lot of them in order, wonderful stuff. But he often refers to two chronometers, e.g. "a handsome pair of chronometers" in the captain's cabin. And there is an episode in which a merchant ship asks for a time fix, because their chronometers have drifted apart and they have been having to navigate on the average of the two. O'Brian's research is so meticulous that I find it hard to believe that he got this wrong, but it's hard to square with Jack London's obvious argument. Do you have an idea about what is going on here?
Indeed, in Desolation Island, the second paragraph of Chapter Five mentions that
Quote:
a perfect sight of the moon and Altair proved that the chronometers he had indulged in--a superlative pair, the pride of their maker--were still within seconds of Greenwich time.
So, what's the story? Did sailing captains sail with three chronometers, or only with "a pair?"

Was it perhaps customary for the owner or the Admiralty to provide a single chronometer, to which prudent captains added "a pair" of their own?

And, was "a pair of chronometers" two separate instruments, or did it consist of two chronometer movements mounted within a single housing?


Sun May 17, 2009 9:28 pm
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Post Re: Three chronometers? Or "a pair?"
Just some comments...

Chronometers were incredibly expensive even after John Harrison's devices were put into production. The cost of chronometers might have been the controlling factor that determined whether a particular ship during a particular year had one, two, or three on board.

I would suggest that, early on, if a ship had three, there were three times to pick between and all three might have been slightly incorrect.

It is true that POB did a lot of research into the British Navy of the era he wrote. Was Jack London’s setting the same?

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Mon May 18, 2009 1:18 am
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Some further rough comments to add to Don’s:

Not every ship of the RN was issued with even one chronometer in Jack Aubrey’s day. Only foreign going ships were supplied, and probably not all of those. Ships in home waters were not issued chronometers until after 1840. As usual, cost had a great deal to do with this. Between 1785 and 1805 the cost of a Earnshaw or Harrison chronometer fell from 120 pounds to between 65 and 80 pounds and even further by 1840. The HEIC was ahead of the RN in ensuring that all of its ships carried a chronometer.

Looking at Cook’s voyages, at a slightly earlier period, the ENDEAVOUR had no chronometer (but Cook was expert in the lunar method). On the second voyage both ships were supplied with two chronometers and the same on the third voyage.

“Two chronometers the captain had,
One by Arnold that ran like mad.
One by Kendal in a walnut case,
Poor devoted creature with a hangdog face…….”

Some captains purchased their own chronometers.
The issue of two or more was probably restricted to voyages of exploration


“In Her Majesty’s Navy it was formerly customary to furnish every ship with one chronometer. If the captain supplied a private one in addition, then the Government gave another, so as to make three chronometers in all. It was argued that if a ship had but one chronometer, it would be unwise implicitly to trust it; and, therefore, great caution was necessary in navigation. If the ship had two, and they happened to differ, it would be impossible to tell which was right. If, however, she had three, the coincidence of any two of them would throw a strong probability on the truth of their results; while the mean of the three could probably be more safely relied on than any one of them taken singly; added to which, the examination of their intercomparisons……..gave the means of detecting which of the three was irregular. By a recent more liberal regulation, the Admiralty now furnish all sea-going ships with three chronometers.”
“Notes on the Management of Chronometers……”, Captain F.A. Shadwell, RN, 1861.

In the merchant service, apart from the Chartered Companies, the practice would have been much more variable, and probably dependent upon the owner’s liberality and the master’s ability to acquire his own.
In 1855 an Act required all British “passenger vessels” to carry at least one chronometer if proceeding to a destination north of the equator and at least two when proceeding south of the equator.

I note that in London’s “The Cruise of the SNARK”, the ship had but one chronometer. London’s setting of his novels was, I think, considerably adrift in time from the period of O’Brian’s interests


Mon May 18, 2009 1:33 am
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Hello dpbsmith,

Welcome to the SN Forum!

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Mon May 18, 2009 2:15 am
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Thanks, Ionia, for your very thorough reply.

I'm sorry to have been vague. I hadn't appreciated the obvious point that practices might have changed over the years, and have been tied to the changing price of chronometers and to the navigational needs of the ship.

No, Jack London wasn't writing about 1650-1850. He was writing in 1915, the story seems to be set in the recent past--very likely the approximate time of his own sailing career on the Sophia Sutherland which was circa 1893. The date isn't mentioned explicitly, but the book has an old sailor, an "ancient mariner," reminiscing about a time "in '52, in 1852, on such a day as this, when we cleared from Sydney in the Wide Awake....

Jack London had a personal library of 15,000 volumes but he was no historical novelist and none of his work gives the impression of being meticulously researched; he treated source material as a lode to be mined for story ideas. Certainly not Michael, Brother of Jerry, a potboiler written in the days when, according to his daughter Joan, "it was obvious that Jack was no longer exerting himself."

He could also have exaggerated or distorted things for the sake of the story.

So whatever he had to say about chronometers likely came from his own experiences or stories he'd heard personally, and probably refers to the late 1800s.


Tue May 19, 2009 12:06 am
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dpbsmith begins a query with:
Quote:
In Michael, Brother of Jerry, a justifiably obscure and extremely bad (trust me on this) novel by Jack London, he mentions that it was the practice to sail with three chronometers, so that if one of them failed to keep time it was possible to tell which of the three it was.


I know that my thoughts on this are totally off-topic, but I was once a research biologist, a field in which mathematical statistics are now extremely important in the analysis of variable data. I recall an eminent researcher who, in order to annoy some statisticians one lunchtime, once said: "If one does a careful study of one cow, one will know all you need to know about that cow. If you do an equally careful study of another cow, then you will have precise data on that cow. If you average your results, you won't know anything useful about either cow" Needless to say, he was actually meticulous in applying statistical analysis to all of his own research.

Martin


Tue May 19, 2009 3:30 pm
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