be diminished.  ’Relying on this, we have now computed our mean refractions by diminishing those of Bessel’s Fundamenta in the proportion of 1 to 0.99797.’—­The Magnetometer-Indications for the period 1858-1863 had been reduced and discussed, with remarkable results.  It is inferred that magnetic disturbances, both solar and lunar, are produced mediately by the Earth, and that the Earth in periods of several years undergoes changes which fit it and unfit it for exercising a powerful mediate action.—­The Earth-current records had been reduced, and the magnetic effect which the currents would produce had been computed.  The result was, that the agreement between the magnetic effects so computed and the magnetic disturbances really recorded by the magnetometers was such as to leave no doubt on the general validity of the explanation of the great storm-disturbances of the magnets as consequences of the galvanic currents through the earth.—­Referring to the difficulty experienced in making the meteorological observations practically available the Report states thus:  ’The want of Meteorology, at the present time, is principally in suggestive theory.’—­In this year Airy communicated to the Royal Astronomical Society a Paper ’On the Preparatory Arrangements for the Observation of the Transits of Venus 1874 and 1882’:  this subject was now well in hand.—­The First Report of the Commissioners (of whom he was Chairman) appointed to enquire into the condition of the Exchequer Standards was printed:  this business took up much time.—­He was in this year much engaged on the Coinage Commission.

Of private history:  There was the usual winter visit to Playford, and a short visit to Cambridge in June.—­From about Aug. 1st to Sept. 3rd he was travelling in Switzerland with his youngest son and his two youngest daughters.  In the course of this journey they visited Zermatt.  There had been much rain, the rivers were greatly flooded, and much mischief was done to the roads.  During the journey from Visp to Zermatt, near St Nicholas, in a steep part of the gorge, a large stone rolled from the cliffs and knocked their baggage horse over the lower precipice, a fall of several hundred feet.  The packages were all burst, and many things were lost, but a good deal was recovered by men suspended by ropes.

In this year also Airy was busy with the subject of University Examination, which in previous years had occupied so much of his attention, as will be seen from the following letters: 

ROYAL OBSERVATORY, GREENWICH,
LONDON, S.E.
1868, March 12.

MY DEAR MASTER,

I have had the pleasure of corresponding with you on matters of University Examination so frequently that I at once turn to you as the proper person to whom I may address any remarks on that important subject.

Circumstances have enabled me lately to obtain private information of a most accurate kind on the late Mathematical Tripos:  and among other things, I have received a statement of every individual question answered or partly answered by five honour-men.  I have collected the numbers of these in a small table which I enclose.