120 



Report of the Kew Committee. 



This was accordingly done, and accurate tracings made of every one 

 of Schwabe's drawings. These were pasted into blank books, and any 

 important notes were transcribed at the same time. 



The Observatory, therefore, now possesses a complete record of the 

 condition of the sun's surface, extending from November, 1825, to the 

 present date. 



The work was performed by the members of the Observatory staff, 

 in extra hours. 



Transit Observations. — Ninety observations have been made of sun- 

 transits, for the purpose of obtaining correct local time at the Obser- 

 vatory : 102 clock and chronometer comparisons have also been made. 



Sunshine Recorder. — The Campbell sunshine recorder, described in 

 the Report for 1875, continues in action, and the improved form of the 

 instrument, giving a separate record for every day of the duration of 

 sunshine, has been regularly worked throughout the year, and its 

 curves tabulated. In April last, the new pattern of card-holder, de- 

 vised by Professor Stokes (" Quarterly Journal Met. Soc," vol. vi, 

 p. 83) was substituted for that previously employed, in order that the 

 records produced by the instrument might be in conformity with 

 those obtained from the other stations of the Meteorological Council. 

 Since that date both cards and tabulations have been transmitted 

 regularly to the Meteorological Office, copies, however, being retained 

 in the Observatory for reference. 



A similar sunshine recorder has been constructed for the Melbourne 

 Observatory, and, after trial and adjustment at Kew, was transmitted 

 together with a set of pattern- cards, through the Crown Agents to 

 Mr. Ellery. 



IY. Experimental Work. 



Winstanleifs Recording Radiograph. — This instrument, designed by 

 Mr. D. Winstanley, as described in " Engineering," vol. xxx, p. 316, 

 for the purpose of registering continuously the amount of radiation 

 from the sky, by mechanical means, upon a sheet of blackened paper, 

 has been erected on the roof of the Observatory since the beginning of 

 August. 



Its indications, which were procured for some weeks, showed it to 

 be a much more delicate appliance than the sunshine recorder or the 

 black bulb thermometer, being affected by changes of radiation from 

 the sky, which take place both at night and when the sky is clouded, 

 as well as when the sun is shining. JSTo use has, however, yet been 

 made of its curves, mainly on account of the difficulty of determining 

 a scale value for them. 



Wind Component Integrator. — This instrument, owing to the causes 

 referred to in last Report, was not kept in action after that date, and 

 in December it was dismounted. It has since been deposited again in 



