law may not be so exceedingly
intricate as to produce a grand sum total of results which, from the
geometrical side, may justifiably be regarded as casual.

The search for evidence of a general plan in the wanderings of the
stars over the face of the sky has so far proved fruitless. Local
concert can be traced, but no widely diffused preference for one
direction over any other makes itself definitely felt. Some regard,
nevertheless, _must_ be paid by them to the plane of the Milky Way;
since it is altogether incredible that the actual construction of the
heavens is without dependence upon the method of their revolutions.

The apparent anomaly vanishes upon the consideration of the
profundities of space and time in which the fundamental design of the
sidereal universe lies buried. Its composition out of an indefinite
number of partial systems is more than probable; but the inconceivable
leisureliness with which their mutual relations develop renders the
harmony of those relations inappreciable by short-lived terrestrial
denizens. "Proper motions," if this be so, are of a subordinate kind;
they are indexes simply to the mechanism of particular aggregations,
and have no definable connection with the mechanism of the whole. No
considerable error may then be involved in treating them, for purposes
of calculation, as indifferently directed, and the elicited solar
movement may genuinely represent the displacement of our system
relative to its more immediate stellar environment. This is perhaps
the utmost to be hoped for until sidereal astronomy has reached
another stadium of progress.

Unless, indeed, effect should be given to Clerk Maxwell's suggestion
for deriving the absolute longitude of the solar apex from
observations of the eclipses of Jupiter's satellites (Proc. Roy. Soc.,
vol. xxx., p. 109). But this is far from likely. In the first place,
the revolutions of the Jovian system cannot be predicted with anything
like the required accuracy. In the second place, there is no certainty
that the postulated phenomena have any real existence. If, however, it
be safe to assume that the solar system, cutting its way through
space, virtually raises an ethereal counter-current, and if it be
further granted that light travels less _with_ than _against_ such a
current, then indeed it becomes speculatively possible, through slight
alternate accelerations and retardations of eclipses taking place
respectively ahead of and in the wa