Xlvi REPORT — 1869. 



the rainfall automatically. A description of this instrument will be submitted 

 to the Association at Exeter. 



Attention is likewise directed to a paper to be communicated by Mr. 

 Balfour Stewart to the Association at the Exeter Meeting, entitled " Eemarks 

 on Meteorological Eeductions, with especial reference to the Element of Va- 

 pour ; " separate copies of which will be at the disposal of Members. 



The following revised fees are charged for tho verification of meteorological 

 instruments at Kew : — 



s. d. 

 Barometers (requiring index- and capacity-corrections) . . 10 

 Ditto (not requiring capacity-correction — inches measured) 5 



Thermometers (ordinary) 1 



Boiling-point Thermometers 2 G 



Hydrometers 1 



3. Photoheliograph. — The Kew Heliograph, in charge of Mr. De La Rue, 

 continues to be worked in a satisfactory manner. During the past year 274 

 negatives have been taken on 168 days : 40 pictures of the Pagoda in Kew 

 Gardens, as a fixed terrestrial object at a known distance, have likewise 

 been taken, with the object of determining, by measurements of these 

 pictures, M'hich are taken in difi'erent parts of the field of the telescope, 

 both the optical distortion of the sun -pictures and the angular diameter of 

 the Sun. 



A paper communicated to the Eoyal Society by Messrs. Warren De La Rue, 

 Stewart, and Loewy, entitled " Researches on Solar Physics. — Heliographieal 

 Positions and Areas of Sun-spots observed with the Kew Photoheliograph 

 during the years 1862 and 1863," is the first of the series of reductions of 

 the photographic solar records ; it is in the course of publication in the 

 ' Transactions ' and will shortly be distributed. 



It is hoped that, during next winter, a paper containing the heliographieal 

 positions and areas of the spots observed at Kew during the years 1864, 

 1865, and 1866 may be communicated to the Royal Society, as well as a 

 paper representing, both numerically and graphically, the spotted area of the 

 sun during three complete solar periods, the results being partly derived 

 from Schwabe's and partly from Carrington's observations, in addition to those 

 made with the Kew photoheliograijh. 



Another paper by the above authors, entitled "Account of some Recent 

 Observations on Sun-spots made at the Kew Observatory," has Hkewise been 

 ordered to be published in the ' Philosophical Transactions.' 



M. Berg, of the Wilna Observatory, has during the past year received 

 instruction at Kew in the method of taking Solar Photographs and in that of 

 measuring the positions and areas of sun-spots, the Du-ector of the Obser- 

 vatory with which he is connected being dcsiro\is of working along with 

 Kew, and of following out the same methods of observation as well as the 

 same researches. 



The number of sun-spots recorded after the manner of Hofrath Schwabe, 

 together with a Table exhibiting the monthly groups observed at Dessau and 

 at Kew for the year 1868, have been communicated to the Astronomical 

 Society, and published in their ' Monthly Notices.' 



We regret to mention that Hofrath Schwabe, owing to his great age, has 

 found it necessary to discontinue his observations ; but the Committee have 

 satisfaction in stating that arrangements have been made for continuing, at 

 Kew, the grouping of sun-observations which has been carried on for some 



