use.

By a report of the Astronomer-royal to the Board of Visitors, who have
lately made their annual inspection of the Greenwich Observatory, we
are informed, of a singular fact, that observations of the pole-star
shew that its position varies some three or four seconds on repeating
the observations at intervals of a few months, and this
notwithstanding the extreme accuracy of the transit circle. The only
explanation which can as yet be given for this phenomenon is, that the
earth, solid as it appears, is liable to slight occasional movements
or oscillations.

We shall know, in a few weeks, the result of the telegraphic
correspondence with the Observatory at Paris--one interesting point
being, as to whether the respective longitudes, as at present
determined, will be verified by the galvanic test. Besides which,
Greenwich time is to be sent every day to London, where a pole, with a
huge sliding-ball, has been fixed on the top of the Telegraph Office,
near Charing Cross. This ball is to be made to descend at one o'clock
simultaneously with the well-known ball which surmounts the
Observatory; and thus scientific inquirers--to say nothing of the
crowds who will daily throng the footways of the Strand to witness the
downcome--will be informed of the true time, while, by means of the
wires, it may be flashed to all parts of the kingdom.

The lecture with which Professor Faraday wound up the course at the
Royal Institution may be mentioned here, seeing that it adds somewhat
to our knowledge of the theory and phenomena of magnetism. As usual,
the lecture-room was crowded; and those who could not understand, had
at least the satisfaction of being able to say they were present. Mr
Faraday, who, enlarging upon his view, announced, a short time since,
that there are such things as magnetic lines of force, now contends
that these lines have a 'physical character'--a point most
satisfactorily proved by sundry experiments during the lecture. The
inquiry is one, as Mr Faraday observes, on the 'very edge of science,'
trenching on the bounds of speculation; but such as eminently to
provoke research. The phenomena, he says, 'lead on, by deduction and
correction, to the discovery of new phenomena; and so cause an
increase and advancement of real physical truth, which, unlike the
hypothesis that led to it, becomes fundamental knowledge, not subject
to change.' A chief point of discussion to which the investigations
have led is: Whethe