476 



Report of the Kew Committee. 



Dr. van Rijckevorsel, of Rotterdam, visited the Observatory to 

 redetermine the constants of his instruments, and make observations 

 of the magnetic elements prior to the commencement of a new 

 magnetic survey of Holland and Belgium, which he has undertaken 

 under the auspices of the Koninklijke Akademie van Wetenschappen 

 te Amsterdam, so as to connect M. Moureaux's survey of France with 

 Dr. Neumayer's survey of Germany. Dr. van Rijckevorsel selected 

 Kew, Wilhelmshaven, and Paris as his base stations. 



Mr. Kitto, Superintendent of the Falmouth Observatory, visited 

 Kew in the spring of the year, to study the methods of constructing 

 tabulating scales for the conversion of the indications of his magneto- 

 graphs into numerical values, in accordance with the recommenda- 

 tions of the International Commission. He also took advantage of 

 the visit to become conversant with the use of the transit instru- 

 ment, one of which has been recently acquired and set up at the 

 observatory under his charge. 



II, Meteorological Observations. 



The several self-recording instruments for the continuous registra- 

 tion respectively of Atmospheric Pressure, Temperature, and Humidity, 

 Wind (direction and velocity), Bright Sunshine, and Rain have been 

 maintained in regular operation throughout the year. 



The standard eye observations for the control of the automatic 

 records have been duly registered, together with the daily observa- 

 tions in connexion with the U.S. Signal Service synchronous system. 

 A summary of these observations is given in Appendix II. 



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 to the 

 Meteorological Office. 



The readings of the old 100-inch area square rain gauge have been 

 discontinued since February, the new 8 -inch circular gauge being 

 now regularly employed, as a check upon the indications of the 

 Beckley self-recording instrument. 



The working standard barometer (Newman, 34) of the Observa- 

 tory, which has been in use continuously since the date of its erection 

 in 1851, having become somewhat worn in its mechanism, was 

 dismounted, and the scale and fittings repaired by Negretti and 

 Zambra, without interfering with the tube and cistern, which were 

 retained at the Observatory. On its return it was again put together 

 and restored to its old place, and fresh comparisons made with the 

 Welsh absolute standards. These showed that a slight shift had 

 taken place in the position of the zero of the scale, a new deter- 

 mination of the scale error was made and fresh corrections accord- 

 ingly adopted. During the period it was under repair the Roval 



