of Mercury are as remote
as 1907, 1914 and 1924, there will be no transit of Venus at all during
the 20th century; not another indeed until A.D. 2004.

From the standpoint of an amateur astronomer the various phenomena which
attend the movements of the satellites of Jupiter, constitute an endless
variety of interesting scenes, which are the more deserving of attention
in that they can be followed with the aid of a telescope of very
moderate size and capabilities.[169]

[Illustration: FIG. 15-16.--OCCULTATION OF JUPITER, AUG. 7, 1889
(_Immersion_)]

Occultations of planets and stars by the Moon may also be recommended to
the notice of the owners of small telescopes as events which are
constantly happening and which may be readily observed. The Moon being
rapidly in motion it will happen in point of fact that stars are
occulted by it, one may say every day, but of course the Moon's light
entirely blots out the smaller stars and only those as large as, say,
about the 5th magnitude are as a rule worth trying to see in this
connection. A table of the occultations of such stars, copied from the
_Nautical Almanac_, will be found in such almanacs as _Whitaker's_ and
the _British_. If such a table is consulted it will be found that never
does a lunation pass without a few stars being noted as undergoing
occultation, and now and then a planet. An occultation of a planet is
obviously still more interesting than that of a star.

[Illustration: FIG. 17-18.--OCCULTATION OF JUPITER, AUG. 7, 1889
(_Emersion_).]

From the epoch of New to Full Moon the Moon moves with its dark edge
foremost from the epoch of Full to New with its illuminated edge
foremost. During therefore the first half of a lunation the objects
occulted disappear at the dark edge and reappear at the illuminated
edge, during the second half of a lunation things are _vice versa_. The
most interesting time for watching occultations is with a young Moon no
more than, say, from 2 to 6 days old, because under such circumstances
the star occulted is suddenly extinguished at a point in the sky where
there seems nothing to interfere with it.

FOOTNOTES:

[Footnote 169: For details as to these matters, see my _Handbook of
Astronomy_, 4th ed., vol. i. pp. 186-196.]

APPENDIX.

THE TOTAL ECLIPSE OF THE SUN OF MAY 28, 1900.

This Appendix deals solely with geographical and transport matters as to
which acc