158 METEOROLOGICAL OBSERVATORIES. 



of the observing staff of an observatory to be dispensed with." 1 This 

 suggestion attracted the notice of two eminent scientific inventors — 

 one, Mr. Claries Brooke, F. R. S., who was my predecessor in this chair 

 in the years 1865-66; the other, Mr. Ronalds, at the time on the staff 

 of the observatory of the British Association at Kew, and who became 

 subsequently its superintendent. Both gentlemen completed their 

 inventions of self-recording magnetographs and meteorographs. The 

 Brooke system was adopted by Sir Gr. Airy at Greenwich, the Ronalds 

 system at Kew. At the date of the reorganization of the meteorolog- 

 ical department of the board of trade, under a committee of the Royal 

 Society, the Ronalds system of photographic barographs and thermo- 

 graphs was adopted for all their observatories and the Kew was con- 

 stituted their central and normal observatory. 



The verification branch of the observatory was first set on foot in 

 connection with magnetic apparatus, and subsequently extended to 

 meteorological and other instruments in the early fifties. 



A walk through the building enables one to form but a very dim 

 estimate of the work carried on there, but by the kindness of Dr. 

 Chree, the superintendent, I have recently had the opportunity of visit- 

 ing the place under favorable auspices. 



As regards meteorology the institution is of incalculable value, for it 

 is here that all English thermometers, with any pretensions to accuracy, 

 are sent for examination and certificate. After being carefully com- 

 pared with a standard in hot water, which is contained in a cistern 

 with a transparent side, and also after being submitted to freezing and 

 boiling temperatures, where necessary, the thermometers, if found cor- 

 rect, are marked by etching the "KO" monogram on the glass, and are 

 sent out to the world with an established character for accurary. 

 Barometers, hydrometers, and other instruments are also severely 

 tested, examined, and marked at Kew, while watches and chronome- 

 ters, after having been duly baked, frozen, tried in various positions, 

 and carefully timed for months, are sent out with a certificate of the 

 number of marks attained in the competition — 100 would mean perfec- 

 tion — and the highest in 1884 reached 88.8. The Kew certificate adds 

 considerably to the selling price of any instrument or watch. Photo- 

 graphic lenses are also examined and certified here, and recently a 

 department has been established for the testing of platinum thermome- 

 ters, a form of instrument which, though of little use to the meteorolo- 

 gist, is essential to the chemist or metallurgist who has to deal with 

 very high temperatures. 



It is at this observatory that the researches into the heights of the 

 various forms of clouds were carried out by the late Mr. Whipple, 

 whom we all so well remember. I show you a photograph of the 

 apparatus he employed, and merely say in passing that the same cloud 

 was at the same instant observed by two telescopes, one of which was 



1 Report of the J5ritish Association, 1845, page 71. 



