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Frank Reed wrote-

>Now how about Slocum? Everyone mentions him when they talk about lunars, but
>reading "Sailing Alone Around the World", it seems that he barely used the
>technique. Is there other evidence (his log book) that he practiced lunars
>during
>his circum-navigation?

And I think somewhere recently (but I can't locate it now) Frank implied
that Slocum used lunars only once in his circumnavigation.

All this is a vile calumny on my favourite voyager! I think Frank should
re-read his Slocum, as I have just done: for the nth time (and a pleasure
each time).

Slocum mentions, early on, that although he owns a chronometer it would
cost $15 to get it cleaned, so he decided to leave it behind. At Yarmouth
he purchased his famous tin clock, the price of which was a dollar and a
half "but on account of the face being smashed the merchant let me have it
for a dollar".

South of Rio, "Spray" exchanged positions with a steamship, and, with her
tin clock, had exactly the same reckoning.

43 days out from Juan Fernandez he says- "If I doubted my reckoning after a
long time at sea I verified it by reading the clock aloft made by the Great
Architect, and it was right."

Nearing Nukahiva (Marquesas), he obtained a lunar longitude that was within
5 miles of his dead reckoning, and when sighting it found that his
longitude was halfway between those two reckonings. He said "even expert
lunarians are acknowledged as doing clever work when they average within 8
miles of the truth." Clever work indeed. But this was after discovering an
error in a logarithmic table that otherwise would have put him many
hundreds of miles out.

Nearing Timor, he says "But the greatest science was in reckoning the
longitude. My tin clock and only timepiece had by this time lost its
minute-hand, but after I boiled her she told the hours, and that was near
enough on a long stretch."

These passages are written in such a way as to imply that the lunar
observations were routine matters that were kept up at regular intervals.
How, otherwise, could he have had lat and long readily at hand to exchange
with that steamship?

However, in mid-Indian Ocean, he does admit- "I hope I am making it clear
that I do not lay claim to cleverness or to slavish calculation in my
reckonings. I think I have already stated that I kept my longitude, at
least, mostly by intuition."

In taking a lunar, the angle changes so slowly that precise timing is
unnecessary. The requirement for extreme precision is in the angle, not in
the time. A clock with an hour hand only could probably be estimated to the
nearest minute or two, which was close enough to relate a morning
time-sight to a measured lunar distance. And it could give a rough measure
of time (and therefore longitude) for a few days thereafter. Even if it had
been boiled. So Slocum's claim isn't impossible.

However, Slocum's son, Captain Victor Slocum, in his biography "Capt.
Joshua Slocum" (1950), thought that the tin-clock business was Slocum's
"joke". Here's what he says, about the days when Joshua was a merchant
captain.

"On one of the Captain's runs in the Constitution between Honolulu and San
Francisco, his chronometer broke down. But as it had always been rated by
lunars, the mishap made no difference so far as navigation of the vessel
was concerned. In fact, on arriving in San Francisco, it was found that the
passage had been unusually short. Mr Bichard, the owner, who was waiting on
the dock, was amazed, and without saying a word about the circumstances of
the voyage, turned on his heel, and returned with the best chronometer
watch, an E. Howard, that money could buy. This he presented to his
Captain, both as a mark of appreciation and a guarantee that he would be
protected against further accidents by having a second timepiece about.

The chronometer breakdown episode throws a light on the navigation of the
Spray which has never been very well understood, owing perhaps to the
Captain's purposeful vagueness on this point. Even professional navigators
have taken his tin clock joke seriously. The Captain meant that he emploted
the same methods in navigating the Spray that he had on all of is former
vessels. In the hands of skilful observers and patient computers the Lunar
Method is reliable within a quarter of a degree longitude, which would be
the distance of a high landfall..."

As for me, I think that Joshua Slocum was a gifted teller of tales, and
don't think we need to accept every word as gospel truth.

George.



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