XXXiv REPORT — 1864<. 



an account will be rendered to that Society. It wiU thus be seen that other 

 experiments and observations of a nature to further science are made at Kew 

 besides those which form the constant work of the Observatory, and of these 

 the Spectroscope measurements at present in progress may be mentioned as 

 an example ; it will also be noticed that the British Association do not bear 

 the expense of these experiments, but this is defrayed by those who bring them 

 before the Committee. 



Prom the financial statement which accompanies this Eeport, it will be 

 seen that the adverse balance of last year ha.s been considerably reduced, 

 but there is stiU a balance against this Observatory amounting to £4-5 17s. 9d. 

 The Committee recommend that a sum of JGOO should be granted for the 

 expenditure of the current year. 



A correspondence, which is appended to this Report, has taken place be- 

 tween the Astronomer Royal and the Chairman, relative to a paragraph con- 

 tained in the Report of the former to the Visitors of the Royal Observato7y, 



The Astronomer Royal has further suggested that certain experiments 

 should be made in this Observatory : — 



1st. Eor the purpose of investigating the discordances which he has found 

 in his observations of the dipping-needle. 



2nd. For the purpose of investigating the displacements which occur in the 

 trace of his vertical -force photograph. 



3rd. On the temperature corrections of the force of a magnet made by 

 heating it in hot air instead of by hot water. 



The Committee, for the reasons contained in the letter of the Superinten- 

 dent (No. VII. Correspondence), considerd that it was not advisable to imder- 

 take the experiments suggested by the Astronomer Royal, as one of these 

 would necessarily involve the displacement of the Kew vertical-force magneto- 

 graph, while the others refer to points which, in the opinion of the Committee, 

 have been already decided by previous observations and experiments. 



J. P. Gassiot, Chairman. 

 Kew Observatory, 



26th August, 1864. 



Correspondence *. 



I. 



Kew Observatory, Eiclunond, 27tli June, 1864. 



Mt dear Sib, — The attention of the Kew Committee has been drawn to 

 the following paragraph in your Report to the Visitors of the Royal Ob- 

 servatory : — 



" I consider it certain that the small probable errors which have been 

 attributed to ordinary needles are a pure delusion. I know no instrumental 

 determination in which, without any breach of faith, the wish for uniformity 

 of results wiU be so certainly followed by uniformity of results as in the 

 determination of dip." 



It having been suggested that the preceding paragraph may possibly be 

 considered to refer to other observations than those made at Greenwich, I 

 am requested by the Committee to inquire whether it is intended in any 

 measure to refer to dip-observations made at this Observatory, and published 

 in the publications of the Royal Society ; the object of the Committee being 

 * A copy of this correspondence was forwarded to the Astronomer Eoyal on 26th August. 



