the course of the year.

Airy's scientific work was, however, by no means confined to the
observatory. He interested himself largely in expeditions for the
observation of eclipses and in projects for the measurement of arcs
on the earth. He devoted much attention to the collection of magnetic
observations from various parts of the world. Especially will it be
remembered that the circumstances of the transits of Venus, which
occurred in 1874 and in 1882, were investigated by him, and under his
guidance expeditions were sent forth to observe the transits from
those localities in remote parts of the earth where observations most
suitable for the determination of the sun's distance from the earth
could be obtained. The Astronomer Royal also studied tidal
phenomena, and he rendered great service to the country in the
restoration of the standards of length and weight which had been
destroyed in the great fire at the House of Parliament in October,
1834. In the most practical scientific matters his advice was often
sought, and was as cheerfully rendered. Now we find him engaged in
an investigation of the irregularities of the compass in iron ships,
with a view to remedying its defects; now we find him reporting on
the best gauge for railways. Among the most generally useful
developments of the observatory must be mentioned the telegraphic
method for the distribution of exact time. By arrangement with the
Post Office, the astronomers at Greenwich despatch each morning a
signal from the observatory to London at ten o'clock precisely. By
special apparatus, this signal is thence distributed automatically
over the country, so as to enable the time to be known everywhere
accurately to a single second. It was part of the same system that a
time ball should be dropped daily at one o'clock at Deal, as well as
at other places, for the purpose of enabling ship's chronometers to