ngth springs out into
sunlight. This illuminated portion will grow more and more extensive at
each succeeding return, the edge of the shadow appearing to recede from
it until it finally passes off at the south. Similarly, when a lunar
eclipse commences as partial at the south of the moon, the edge of the
shadow at each subsequent recurrence finds itself more and more to the
northward. In due course the total phase will supervene, and will
persist during a number of recurrences until the southerly trend of the
moon results in the uncovering of the lunar surface at the south. Thus,
as the boundary of the shadow is left more and more to the northward,
the illuminated portion on the southern side of the moon becomes at each
recurrence greater and the darkened portion on the northern side less,
until the shadow eventually passes off at the north.

The "life" of an eclipse of the moon happens, for certain reasons, to be
much shorter than that of an eclipse of the sun. It lasts during only
about 860 years, or 48 saros returns.

Fig. 6, p. 81, is a map of the world on Mercator's Projection, showing a
portion of the march of the total solar eclipse of August 30, 1905,
across the surface of the earth. The projection in question has been
employed because it is the one with which people are most familiar. This
eclipse began by striking the neighbourhood of the North Pole in the
guise of a partial eclipse during the latter part of the reign of Queen
Elizabeth, and became total on the earth for the first time on the 24th
of June 1797. Its next appearance was on the 6th of July 1815. It has
not been possible to show the tracks of totality of these two early
visitations on account of the distortion of the polar regions consequent
on the _fiction_ of Mercator's Projection. It is therefore made to
commence with the track of its third appearance, viz. on July 17, 1833.
In consequence of those variations in the apparent sizes of the sun and
moon, which result, as we have seen, from the variations in their
distances from the earth, this eclipse will change from a total into an
annular eclipse towards the end of the twenty-first century. By that
time the track will have passed to the southern side of the equator. The
track will eventually leave the earth near the South Pole about the
beginning of the twenty-sixth century, and the rear portion of the
partial shadow will in its turn be clear of the terrestrial surface by
about 2700 A.D., when