1881. J of some Experiments with Whirled Anemometers. Ill 



carried out by Mr. Scott himself, but were entrusted to Mr. Samuel 

 Jeffery, then Superintendent of the Kew Observatory, and Mr. G. M. 

 Whipple, then First Assistant, the present Superintendent. 



The results have never hitherto been published, and I was not aware 

 of their nature till on making a suggestion that an anemometer of the 

 Kew standard pattern should be whirled in the open air, with a view 

 of trying that mode of determining its proper factor, Mr. Scott 

 informed me of what had already been done, and wrote to Mr. 

 Whipple, requesting him to place in my hands the results of the most 

 complete of the experiments, namely, those carried on at the Crystal 

 Palace, which I accordingly obtained from him. The progress of the 

 enquiry may be gathered from the following extract from Mr. Scott's 

 report in returning the unexpended balance of the grant. 



" The comparisons of the instruments tested were first instituted in 

 the garden of the Kew Observatory. This locality was found to 

 afford an insufficient exposure. 



" A piece of ground was then rented and enclosed within the Old 

 Deer Park. Th6 experiments here showed that there was a consider- 

 able difference in the indications of anemometers of different sizes, 

 but it was not possible to obtain a sufficient range of velocities to 

 furnish a satisfactory comparison of the instruments. Experiments 

 were finally made with a rotating apparatus, a steam merry-go-round, 

 at the Crystal Palace, which led to some results similar to those 

 obtained by exposure in the Deer Park. 



" The subject has, however, been taken up so much more thoroughly 

 by Drs. Dohrandt and Thiesen {vide " Repertorium fur Meteoro- 

 logie," vols, iv and v) and by Dr. Robinson in Dublin, that it seems 

 unlikely that the balance would ever be expended by me. I, there- 

 fore, return it with many thanks to the Government Grant Com- 

 mittee. 



" The results obtained by me were hardly of sufficient value to be 

 communicated to the Society." 



On examining the records, it seemed to me that they were well 

 deserving of publication, more especially as no other experiments of 

 the same kind have, so far as I know, been executed on an anemo- 

 meter of the Kew standard pattern. In 1860 Mr. Glaisher made 

 experiments with an anemometer whirled round in the open air at 

 the end of a long horizontal pole,* but the anemometer was of the 

 pattern employed at the Royal Observatory, with hemispheres of 

 3*75 inches diameter and arms of 6*725 inches, measured from ihe 

 axis to th j centre of a cup, and so was considerably smaller than the 

 Kew pattern. The experiments of Dr. Dohrandt and Dr. Robinson 



* " Greenwich Magnetical and Meteorological Observations," 1862, Introduction, 

 p. li. 



