REPORT OF THE KEW COMMITTEE. XXXIX 



ing as a member of the British Association, I think that the Ke-w Observatory- 

 would be better employed in that way than in the course which now absorbs 

 so much of its strength. It was originally intended, and in my opinion 

 wisely intended, for the verification and improvement of instruments, and 

 not for continuous observations. If the examination which I propose should 

 be taken up, I should bo happy to cooperate, by repetition of observations 

 (as my opportunities might serve), and by communication of my results." 



These words, while they imply a request which has been courteously 

 acknowledged by you in your reply, appear also to convey the idea that the 

 Kew Observatory has left the biu-den of an experimental iuquiiy regarding 

 dip-circles to the Greenwich establishment, which is not well suited to un- 

 dertake such a task. 



I think that, whatever opinion be entertained regarding the functions of 

 the Kew Observatory, it may be shown that it has fulfilled its duties as 

 respects the dip-circle. I give you the following short sketch of our con- 

 nexion as an obseiwatory with this problem. 



The Kew Committee, being desirous to promote the construction and em- 

 ployment of improved magnetical instruments, procured a dip-circle which 

 was too little known, but which they had reason to think was a good practical 

 instrument. In making monthly determinations of the dip with this instru- 

 ment at Kew, and in bringing these before the notice of men of science, the 

 Committee have given the most convincing experimental proof which it was 

 in their power to afford of the excellence of this instnmient, and they have 

 the satisfaction to think that their work has not been in vain, for the 

 directors of many foreign observatories have supplied themselves with these 

 circles, and as many as could do it have personally inspected them at Kew. 

 Mr. Airy appears to have adopted a different course ; as far as I am aware, 

 he has not yet honoured us with a visit to Kew, in order to inspect our dip- 

 circle and become personally acquainted with oirr method of observation. 

 On the other hand, he has instituted experiments of his own, but has not 

 succeeded in producing a good instrument, and the results which he has thus 

 obtained have induced him to beUeve that the Kew determinations (although 

 made with a different instrument, which is also handled in a somewhat 

 different manner) are not correct. 



The Kew Committee have combated this conclusion, and are not shaken 

 in their belief that they have obtained a nearly perfect dip-circle. They 

 may be right or wrong in this opinion ; but while they retain it they cannot 

 surely be justly reproached with having left to the Greenwich Observatory 

 the burden of an experimental inquiry which they can only regard as super- 

 fluous and self-imposed. 



I remain, my dear Sir, 

 To J. P. Gassiot, Esq., F.B.S., Yours very truly. 



Chairman of the Kew Committee, (Signed) B. Stewart. 



V. 



Eoyal Observatory, Greenwich, July 11, 1864*. 

 Mt dear Sir, — You were so good as to hold out to me the expectation 

 that probably the Kew Observatory Committee might be able to assist this 

 observatory in some important examinations of discordances in the results 

 of magnetic observations, which have given me great anxiety and trouble. 

 To bring this matter more distinctly to a point I wLU indicate three subjects, 



* At the date of this letter Mr. Airy had not received a copv of Mr. Stewart's letter of 

 July 4th. 



