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To Herbert:

Yes, I fully agree that "science" and "art" were synonyma in the history of
navigation (and other branches). I only wonder, if this was still true for
the end of 19th century, albeit for the older man Slocum. From my three
objections, this is the weakest one. The native speaker competent in the
older English and language of sailors of that times maybe could give an
answer.

But I cannot consider Herbert's "working hypothesis" about Slocum's mixing
the headers of column to be probable. If Slocum had been made such mistake
(that everybody makes from time to time), why for the hell he would have
been written about it, after he had corrected himself? He had the option to
stress the accuracy of his lunar observation and to finish the paragraph.
But he was clearly proud of being able to correct the tables that he
depended on and wrote about it very satisfied.

It is not possible that he would have got the wrong value by mistake, then
the right one in the second run (in the same table) and that he would have
related both values to the same argument, the first erroneous, the second
correct and claimed to find the error of table - eh?

I understand his sentence "the column of figures from which [he] had got an
important logarithm
was in error" in quite another way. It is the trace of the ordinary use of
tables, when navigator firstly finds the correct row and then he runs
horizontally to the right column. Slocum's "column of figures" would then be
"the number in the pertinent column".

If Slocum used the most widely used tables for clearing lunars, i.e.
Thomson's tables, he was in the position to amend some their values easily.
Several tables of this table set (not the main table!) give values that can
be easily computed with the help of  common logarithmical tables. These
values are given only to reduce the number of steps. They can be proved and
corrected if a
misprint is realized (which is essential!).


Jan Kalivoda

   

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