fixed on solid piers of masonry, deeply imbedded
in the earth, to secure freedom from vibration--a quality better
obtained when the foundations are on sand or gravel than when on rock.

To describe the instruments by their technical names, and to go into any
particulars of the instruments they have superseded, would take space,
only to do the work of a scientific treatise. Enough, therefore, to say,
that there are the telescopes best adapted to the chief duty of the
place, which is, watching the moon whenever she is visible; watching the
_clock-stars_, by which the true time is calculated more exactly than it
could be from observations of the sun alone; and watching other
planetary bodies as they pass the meridian. Eclipses, occultations, and
other phenomena, of course, have their share of attention, and add to
the burden of the observer's duties.

The staff of the Observatory includes a chief astronomer, Mr. Airy, with
a salary of L800 a year; and six assistants who are paid, L470, L290,
L240, L150, L130, and L130, respectively. This does not include the
officers of the Meteorological branch of the establishment, to be spoken
of hereafter; and which consists of Mr. Glaisher, with L240 a year, one
assistant at L120, and two additional computers. At times, when these
scientific laborers have collected more observations than they are able
to work out; additional help is summoned, in shape of the body of
scientific clerks before spoken of; who, seated at desks, cast up the
accounts the planetary bodies, including such regular old friends as the
moon and fixed stars, but not forgetting those wandering celestial
existences that rush, from time to time, over the meridian, and may be
fairly called the chance customers of the astronomer.

Though the interior of the Observatory seems so still, the life of those
employed there has its excitements. Looking through telescopes forms a
small part only of their duty--and that duty can not be done when the
weather is unfavorable. On cloudy days the observer is idle; in bright
weather he is busy; and a long continuance of clear days and nights
gives him more employment than he can well complete. Summer, therefore,
is his time of labor; winter his time of rest. It appears that in our
climate the nights, on the whole, are clearer than the days, and
evenings less cloudy than mornings. Every assistant takes his turn as an
observer, and a chain of duty is kept up night and day; at other
p