1879.J 



President's Address. 



423 



The unfavourable weather which has characterised the present year, 

 has given an additional impulse to the study of English Meteorology ; 

 and our own Meteorological Office has ventured to resume the issue of 

 Daily Forecasts of Weather, after they had been discontinued for nearly 

 thirteen years. The attempt has been made under somewhat adverse 

 circumstances, as the uncertainty of the weather of 1879 has even 

 surpassed the proverbial fickleness of the British climate. But the 

 experiment has been liberally supported by the Press, and has been 

 watched with great interest by the public generally. Of its success 

 or failure it would as yet be premature to speak, but it deserves 

 recognition as a serious attempt to apply to one of the most uncertain 

 of the sciences the severe test of prediction. 



Transit of Venus (1874) Reductions.— The calculations of every 

 kind relating to the five British Expeditions were some time ago con- 

 cluded. The mass of them refers to the determinations of terrestrial 

 longitudes and the discussion of the measurements of photographs. 

 The preparation of the Astronomical (as distinguished from the 

 Photographic) Observations and Results for Printing is complete for 

 the expeditions to the Hawaiian Islands, Rodriguez Island, and New 

 Zealand. For the other two expeditions much remains to be done — 

 chiefly, however, mere copying. The employment of the staff upon 

 the measurement, re-measurement, and discussion of the photographs, 

 was the most serious cause of the delay that has occurred in present- 

 ing to the public the astronomical results. Those who are now 

 engaged upon this subject entertain serious doubts as to whether 

 any result of value, as regards the special object of the expeditions, 

 is to be expected from the photographs, owing to a want of sharp- 

 ness in the images. Some of the photographs taken by the Russian 

 Astronomers* have been measured, but not very successfully. The 

 telescopic observations of the internal contacts, at many stations in 

 India and Australia, as well as at those occupied by the Government 

 Observers, in all thirty-one observations of the Ingress and forty- 

 eight of the Egress, have yielded a value of the mean solar parallax 

 of 8"-85±0"'03.t 



The Greenwich Nine- Year Catalogue of 2,2G3 stars, with discussions 

 of the systematic errors of R.A.'s and 1ST. P. D.'s has been published. 



The complete reduction of the measures of about 1,900 photo- 

 graphs of the sun, taken at Greenwich from 1873 up to the present 

 time, affords data immediately available for determining the dis- 

 tribution of spots and faculse on the sun's surface, and the position 

 of its axis of rotation. The photographs now regularly taken at 

 Greenwich may be considered a continuation of the Kew series. 



The reduction of the Greenwich magnetic observations, 1841 — 



* At Haven Possuit. 



f " Monthly Notices, E.A.S.," xxxviii, p. 455. 



