on is one of
doubt on the certainty of equality of parts in the scale employed. An
error depending on this cause could not be diminished by any
repetition of observations."--After referring to the desirability of
vigorously prosecuting the Meteorological Reductions (already begun)
and of discussing the Magnetic Observations, the Report concludes
thus: "There is another consideration which very often presents itself
to my mind; the waste of labour in the repetition of observations at
different observatories..... I think that this consideration ought not
to be put out of sight in planning the courses of different
Observatories."--In this year De Launay's Lunar Theory was
published. This valuable work was of great service to Airy in the
preparation of the Numerical Lunar Theory, which he subsequently
undertook.--In the latter part of this year Airy was elected President
of the Royal Society, and held the office during 1872 and 1873. At
this time he was much pressed with work, and could ill afford to take
up additional duties, as the following quotation from a letter to one
of his friends shews: "The election to the Presidency of R.S. is
flattering, and has brought to me the friendly remembrances of many
persons; but in its material and laborious connections, I could well
have dispensed with it, and should have done so but for the respectful
way in which it was pressed on me."

Of private history: There was the usual winter visit to Playford.--In
April he made a short trip to Cornwall with his daughter Annot.--In
June he was appointed a Companion of the Bath, and was presented at
Court on his appointment.--Mrs Airy was staying with her daughter, Mrs
Routh, at Hunstanton, during June, her state of health being somewhat
improved.--From August 1st to 28th he was chiefly in Cumberland, at
Barrow House, and at Grange, Borrowdale, where his son Osmund was
staying for a holiday.

1872

"From the Report to the Board of Visitors it appears that 'The Normal
Siderial Clock for giving sidereal time by galvanic communication to
the Astronomical Observatory was established in the Magnetic Basement
in 1871, June; that locality being adapted for it on account of the
uniformity of temperature, the daily changed of temperature rarely
exceeding 1 deg. Fahrenheit. Its escapement is one which I suggested many
years ago in the Cambridge Transactions; a detached escapement, very
closely analogous to the ordi