422 



The National Physical Laboratory. 



A correction has been applied for the diurnal variation of tempera- 

 ture, use being made of the records from a Richard thermograph as well 

 as of the eye observations of a thermometer placed under the Vertical 

 Force shade. 



The mean values at the noons preceding and succeeding the selected 

 quiet days are also given, but these of course are not employed in 

 calculating the daily means or inequalities. 



The following are the mean results for the entire year : — 



Mean Westerly Declination 16° 5 2'* 7 



Mean Horizontal Force 0-18428 C.G.S. unit. 



Mean Inclination 67° 1 1'*8 



Mean Vertical Force 0-43831 C.G.S. unit. 



Observations of absolute declination, horizontal intensity, and incli- 

 nation have been made weekly as a rule. 



A table of recent values of the magnetic elements at the Observa- 

 tories whose publications are received at Kew will be found in 

 Appendix Ia to the present Report. 



A course of magnetic instruction was given to Captain Denholm 

 Fraser, R.E., charged with a magnetic survey of India, and facilities 

 were afforded him for making experiments with a view to improving 

 the instrumental outfit for the survey. 



A new magnetic hut was erected early in the year by Mr. Eldridge. 

 It is larger and better lighted than the old hut, and has proved very 

 useful. 



II. Meteorological Observations. 



The several self-recording instruments for the continuous registra- 

 tion of Atmospheric Pressure, Temperature of Air and Wet-bulb, 

 Wind (direction, pressure and velocity), Bright Sunshine, and Rain 

 have been maintained in regular operation throughout the year, and the 

 standard eye observations for the control of the automatic records 

 have been duly registered. 



The tabulations of the meteorological traces have been regularly 

 made, and these, as well as copies of the eye observations, with notes 

 of weather, cloud, and sunshine, have been transmitted, as usual, to the 

 Meteorological Office. 



With the sanction of the Meteorological Council, data have been 

 supplied to the Council of the Royal Meteorological Society, the 

 Institute of Mining Engineers, and the editor of ' Symons' Monthly 

 Meteorological Magazine.' On the initiative of the Meteorological 

 Office, some special cloud observations have been made in connection 

 with the International scheme of balloon ascents. 



Eledrograph. — This instrument worked generally in a satisfactory 

 manner during the year. 



The small glass beaker mentioned in last year's Report is still 



