-166 Report of the Kew Committee. 



and the following clocks are kept carefully rated in addition as time- 

 keepers of the Observatory : French ; Shelton K. O. ; Shelton No. 35 ; 

 and Dent 2011. By the courtesy of Mr. Preece, Superintendent 

 of Telegraphs, the Richmond Chief Post Office was placed in direct 

 communication with the Royal Observatory, Greenwich, on January 22, 

 and enabled to receive the time signal at 10 A.M., when a period of 

 cloudy weather had rendered the true time a little uncertain. Two 

 chronometers conveyed to the Post Office, showed, on comparison with 

 the signal, a satisfactory agreement between the times as kept at the 

 two Observatories. 



IV. EXPERIMENTAL WORK. 



Actinometry. A report on the Balfour Stewart actinometer observa- 

 tions made last year, was submitted in December to the Meteorological 

 Council, at whose expense the observations were carried on, and it 

 was resolved to discontinue them. The instrument has since been 

 returned to Professor Balfour Stewart at his request. 



Fog Gauge. In conformity with a suggestion contained in an 

 article in " Symons's Meteorological Magazine," vol. xviii, p. 58, a 

 painted board has been set up to the north of the Observatory, to serve 

 as a gauge for measuring the intensity of fogs. 



Since its erection in January last no fog, however, has been 

 observed of intensity 1 on its scale. 



Magnetic Survey of Great Britain and Ireland. With reference to 

 this, the Sub-Committee appointed last year has now under considera- 

 tion the details necessary for the early prosecution of the survey. 



Professors Rllcker and Thorpe have during the past summer made 

 preliminary observations at a number of stations along the West 

 Coast of Scotland, their base observations being made at the Obser- 

 vatory as above stated. 



Nocturnal Radiation. Experiments have been made with a new 

 pattern thermometer, designed by Messrs. Negretti and Zambra for 

 observations of nocturnal terrestrial radiation, with a view to the 

 avoidance of several serious defects in the Rutherford Minimum, now 

 generally used. Very favourable results were obtained until the 

 instrument was damaged, and had to be sent back to the makers. It 

 has not yet been returned to the Observatory. 



Photo-nephograpTi.- Various experiments have been made with this 

 apparatus during the year, but in consequence of the short base line 

 obtainable with the small amount of connecting wire available for 

 working the pair of cameras, very few satisfactory determinations of 

 cloud altitudes have been made. 



A report having, however, been submitted to the Meteorological 

 (Council, that body has granted a sum of 40Z. to the Committee 



