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 wake of the sun, to determine his
absolute path in space as projected upon the ecliptic. That is to say,
the longitude of the apex could be deduced together with the resolved
part of the solar velocity; the latitude of the apex, as well as the
component of velocity perpendicular to the plane of the ecliptic,
remaining, however, unknown.

The beaten track, meanwhile, has conducted two recent inquirers to
results of some interest. The chief aim of each was the detection of
systematic peculiarities in the motions of stellar assemblages after
the subtraction from them of their common perspective element. By
varying the materials and method of analysis, Prof. Lewis Boss,
Director of the Albany Observatory, hopes that corresponding
variations in the upshot may betray a significant character. Thus, if
stars selected on different principles give notably and consistently
different results, the cause of the difference may with some show of
reason be supposed to reside in specialties of movement appertaining
to the several groups. Prof. Boss broke ground in this direction by
investigating 284 proper motions, few of which had been similarly
employed before (_Astr. Jour._, No. 213). They were all taken from an
equatorial zone 4° 20' in breadth, with a mean declination of +3°,
observed at Albany for the catalogue of the Astronomische