These things being premised, it will be readily understood that outline
forms sufficient for an entire series of lunars will extend over many
pages--they will, in fact, require eighteen pages. There are four sets of
observations for time:--one E. and one W., both at beginning and close of
the whole; one for latitudes N. and S.; six for six sets of lunars, as
described above; six for the corresponding altitudes of the stars, which
have to be computed; and, finally, one page for taking means, and
recording the observations for adjustment, etc. Each double observation
for latitude would take one page; each single time observation one page;
and each single compass variation one page. An occulation would require
three pages in all; one of which would be for time. At this rate, and
taking the observations mentioned above, a book of 500 pages would last
half a year. Of course where the means of transport is limited,
travellers must content themselves with less. Thus Captain Speke, who
started on his great journey amply equipped with log-books and
calculation-books, such as I have described, found them too great an
incumbrance, and was compelled to abandon them. The result was, that
though he brought back a very large number of laborious observations,
there was a want of method in them, which made a considerable part of his
work of little or no use, while the rest required very careful treatment,
in order to give results commensurate with their high intrinsic value.
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