e magnetical results since 1863: In the study of the forms of the
individual curves; their relations to the hour, the month, the year;
their connection with solar or meteorological facts; the conjectural
physico-mechanical causes by which they are produced; there is much to
occupy the mind. I regret that, though in contemplation of these
curves I have remarked some singular (but imperfect) laws, I have not
been able to pursue them.--The mean temperature of the year 1879 was
46.1 deg., being 3.3 deg. below the average of the preceding 38 years. The
highest temperature was 80.6 deg. on July 30, and the lowest 13.7 deg. on
Dec. 7. The mean temperature was below the average in every month of
the year; the months of greatest deviation being January and December,
respectively 6.8 deg. and 7.6 deg. below the average; the months of April,
May, July, and November were each between 4 deg. and 5 deg. below the average.
The number of hours of bright sunshine, recorded with Campbell's
Sunshine Instrument, during 1879, was only 983.--In the summer of 1879
Commander Green, U.S.N., came over to this country for the purpose of
determining telegraphically the longitude of Lisbon, as part of a
chain of longitudes extending from South America to Greenwich. A
successful interchange of signals was made with Commander Green
between Greenwich and Porthcurno on four nights, 1879, June 25 to
29. The results communicated by Commander Green shew that the
longitude of Lisbon Observatory, as adopted in the Nautical Almanac,
requires the large correction of +8.54".--With regard to the coming
Transit of Venus in 1882: From the facility with which the
requirements for geographical position are satisfied, and from the
rapid and accurate communication of time now given by electric
telegraph, the observation of this Transit will be comparatively easy
and inexpensive. I have attached greater importance than I did
formerly to the elevation of the Sun.... I remark that it is highly
desirable that steps be taken now for determining by telegraph the
longitude of some point of Australia. I have stated as the general
opinion that it will be useless to repeat photographic observations.
--In April Mr Barlow called, in reference to the Enquiry on
the Tay Bridge Disaster. (The Bridge had been blown down on
Dec. 28th, 1879.) I prepared a memorandum on the subject for the Tay
Bridge Commission, and gave evidence in a Committee Room of the House
of Lords on Apr. 29th."