Endnote 48
Part II, §17.  This conclusion, as pointed out in the footnote, is not correct in theory, but can be made nearly so in practice, by taking the two altitudes very near the meridian.  This is directly implied in the words `passeth any-thing the sowth westward', i.e. passes ever so little westward of the south line; cf. note below to 38. 10.  Consequently, the first observation must also be taken very near the meridian.