REPORT OF THE KEW COMMITTEE. xlvil 



1. Aggregate of clistui'bancc tending to increase the numerical values. 



2. Aggregate of disturbance tending to decrease the same. 



3. Solar-diurnal range of the undisturbed observations. 



They suggest that the monthly results embodying these facts should be 

 published in detail. 



Finally, they propose to continue the discussion of tlie Lunar-Diurnal 

 variations commenced by Sir E. Sabine, and carried on by him up to the end of 

 the year 1864. In order to work this scheme with sufficient rapidity to com- 

 plete it before the autumn of 1872, additional assistance has been procured, the 

 expense of which has been defrayed by the Chairman. Mr. "Whipple, Mag- 

 netical Assistant, has displayed much zeal and ability in organizing the work 

 and in superintending its immediate execution. 



Already the hourly numerical values of the three magnetic elements have 

 been obtained and tabulated in monthly forms from the commencement of 

 the series in 1858 to the present date ; and considerable progress has also been 

 made in the next step of the reduction. 



A Unifilar, formerly em^jloyed by Captain Haig, and of which the constants 

 have been determined at the Observatory, has been lent to Lieut. Elagin, of 

 the Russian Navy, for use in the Japanese seas and elsewhere. 



A Dip-circle by Dover has been verified and sent to Prof. JeHnek, of 

 Vienna, and another, by the same maker, has been verified for Dr. A. B. 

 i[eyer, for use in the East Indies. This gentleman has likewise received 

 magnetic instruction at the Observatory. 



A Dip-circle by Adie, furnished with a deflecting cylinder aj^paratus, has 

 been verified and dispatched to Prof. Bolzani, of the University of Kasan. 



Three Dipping-needles have likewise been constructed for Dr. Bergsma, of 

 Batavia, and one for Mr. Chambers, of the Colaba Observatory, Bombay. 



A Deflection-bar has been procured and verified for the Eussian Central 

 Observatory. A Dechnometer has been sent to the Lisbon Observatory, and 

 a Fox's Circle has been lent to Dr. Keumayer, after having been repaired by 

 Adie. 



The instrument de\-ised by Mr. Broxm for the purpose of estimating the 

 magnetic dip by means of soft iron, and constructed at the expense of the 

 British Association in pursuance of a resolution of that Body passed at the 

 Oxford Meeting, has been forwarded to that gentleman at his request. 



The usual monthly absolute determinations of the magnetic elements con- 

 tinue to be made by Mr. Whipple, Magnetic Assistant. 



A paper erabodying the results of the absolute observations of Dip and 

 Horizontal Force, made at Kew from April 1863 to April 1869, has been 

 communicated by the Superintendent to the Eoyal Society, and published in 

 the ' Proceedings ' of that body. The results obtained evidence the accuracy 

 with which the monthly observations have been made bj- Mr. Whipple. 



The Self-recording Maguetographs are in constant operation as heretofore, 

 also under his charge ; and the photographic department connected with these 

 instruments remains under the charge of Mr. Page. 



2. Meteorohgical worJc. — The meteorological work of the Observatory 

 continues in the charge of Mr. Baker. 



Since the Exeter Meeting, 150 Barometers have been verified, and 30 have 

 been rejected ; 11 60 Thermometers and 103 Hydrometers have likewise been 

 verified. Nineteen Standard Thermometers have been constructed for Prof. 

 Tait, and two for the Meteorological Ofiice. 



The self-recording meteorological instruments now in work at Kew will 



