1866.] General Sabine — Note on Meteorological Correspondence, 33 



report of Mr. Ronalds, its Director, published in the volume of the British 

 Association for 1847, Trans, of Sections, page SO. "The preliminary 

 experiments on the photographic registration of the atmospheric electro- 

 meter, the thermometer, the barometer, and the declination-magnet having 

 been long since completed and published, and their results having warranted 

 the cost and trouble of constructing apparatus of a durable and convenient 

 character, a declination-magnet and a barometer have been mounted at Kew 

 which scrupulously fulfil the requisite conditions without the intervention of 

 those friction-rollers, levers, pivots, or other mechanism which have hitherto 

 rendered self-registering apparatus so objectionable." Mr. Ronalds added 

 that it was his " intention to provide during the ensuing year complete 

 apparatus on Hke principles for registering as many of the other meteoro- 

 logical and magnetical instruments as funds will permit." 



The instruments which would be required for a complete equipment of a 

 meteorological observatory would be those which should automatically and 

 continuously record (1) the variations of the atmospheric pressure; (2) 

 those of the dry and wet thermometers ; (3) those of the force and direc- 

 tion of the wind ; and (4) those of the atmospheric electricity. Of these, 

 Nos. 1 and 2, as has been already said, had been devised at Kew in or 

 before 1847. Dr. Robinson's hemispherical-cup anemometer, of which a 

 description was published in 1 85 1 in the Transactions of the Royal Irish 

 Academy, and which v/as immediately adopted at Kew, records, in a man- 

 ner which I believe is universally held to be unexceptionable, the direction 

 and force of the wind at every instant. The electrometer to which Mr. 

 Ronalds referred in his report of 1847, though highly ingenious and yield- 

 ing very instructive results, was not continuously self-recording. An 

 electrometer fulfilling this condition was consequently a desideratum until 

 Professor William Thomson devised, and caused to be constructed under 

 his own superintendence at Kew, in the spring of 1861, the self-recording 

 electrometer which has been subsequently in successful work at that ob- 

 servatory ; thus supplying the fourth apparatus required for a complete 

 meteorological record. It m.ay be added that the Kew Barograph photo- 

 graphs its records self-compensated for temperature ; its curves conse- 

 quently are in immediate readiness for the lithographer or engraver. 



Such was the state of instrumental preparation at the Kew Observatory 

 when the untimely death of Admiral FitzRoy, who had been placed by the 

 Board of Trade in charge of the meteorological office estabhshed in 1855, 

 occasioned a renewal of the communications which had taken place on the 

 formation of the office, between the Board of Trade and the Royal Society. 

 In a letter dated May 26, 1865, the Board of Trade recalled to the recol- 

 lection of the Royal Society the recommendations regarding marine meteo- 

 rology contained in the letter of the President and Council of February 

 22, 1855, stating that those recommendations had been adopted by the 

 Board as the basis of the proceedings of the meteorological department ; 

 and that in conformity therewith instruments and logs had been prepared 



