ntation
was celebrated by a Banquet at the Mansion House on Saturday July 3rd,
1875, to Sir George Airy (Astronomer Royal) and the Representatives of
Learned Societies.

There is no doubt that Airy was extremely gratified by the honour that
he had received. It was to him the crowning honour of his life, and
coming last of all it threw all his other honours into the shade. To
his independent and liberal spirit there was something peculiarly
touching in the unsolicited approbation and act of so powerful and
disinterested a body as the Corporation of the City of London.

CHAPTER IX.

AT GREENWICH OBSERVATORY FROM JANUARY 1ST, 1876,
TO HIS RESIGNATION OF OFFICE ON AUGUST 15TH,
1881.

1876

"At the door from the Front Court to the staircase of the Octagon Room
(the original entrance to the Observatory as erected by Sir
Christopher Wren), a small porch-shelter has been often desired. I
proposed to fix there a fan-roof of quadrantal form, covering the
upper flat stone of the external steps.--On a critical examination of
the micrometer-screws of the Transit Circle it was found that the
corrections, which range from -1 deg.38" to +0 deg.76", indicate considerable
wear in the screws; and it was found that as much as one-hundreth part
of an inch had been worn away from some of the threads. The old screws
were consequently discarded, and new ones were made by Mr Simms.--The
adjustment of the Spectroscope has occupied a great deal of
attention. There was astigmatism of the prisms; and false light
reflected from the base of the prisms, causing loss both of light and
of definition. The latter defect was corrected by altering the angles,
and then astigmatism was corrected by a cylindrical lens near the
slit. The definition in both planes was then found to be perfect.--The
number of small planets has now become so great, and the interest of
establishing the elements of all their orbits so small,--while at the
same time the light of all those lately discovered is very faint, and
the difficulty and doubt of observation greatly increased,--that I
have begun to think seriously of limiting future observations to a
small number of these objects.--All observations with the Spectroscope
have been completely reduced; the measures of lines in the spectra of
elements being converted into corresponding wave-lengths, and