Z_ 
REPORT OF THE KEW COMMITTEE. XXXV 
«For practical daily purposes, a self-registering Barometer, on the Milne 
principle, may be sufficient ; but for elaborate analysis of atmospherical con- 
ditions and changes, in connexion with the numerous influences operating, 
some occasionally, some frequently, others always, in the air and its ever- 
restless currents, such an apparatus as that now available at Kew would 
appear to be indispensable. 
« Besides ordinary meteorological peculiarities, the direction of magnetic 
earth-currents, the occurrence of magnetic storms, the differing electrical 
conditions of various currents of air, the phenomena of earthquakes, and 
their ‘lightnings’*, seem to be more or less in certain relations to atmo- 
spheric tension, and therefore to require a close and unbroken barometrical 
registration. Towards some additional expense incurred by the Kew Ob- 
servatory in complying with this request, I am authorized to say that this 
department will contribute, on principle similar to that of verification of 
instruments. 
‘«‘T have the honour to be, 
“c Sir, 
** Your obedient Servant, 
(Signed) “ Ropert FrrzRoy, BR. Adm,” 
«P.S. Probably two scales of tracing, analogous to ‘Sailing Charts’ and 
‘Particular Plans,’ would be convenient.” 
“ John Peter Gassiot, Esq., F.R.S., 
Chairman of the Kew Committee of the 
British Association.” 
To which the Chairman shortly afterwards replied in the following 
terms :— 
(Copy-) 
“Kew Observatory, 23rd April, 1862. 
“Srr,—I have the honour to acknowledge receipt of your letter of 7th 
 inst., addressed to me as Chairman of the Kew Committee of the British 
Association. 
On behalf of this Committee, I may state in reply that it will afford us 
much satisfaction to furnish your department with Photographic Self- 
registrations of the state of the Barometer at Kew Observatory. 
“Tam informed by Mr. Stewart, our Superintendent, that we have in our 
_ possession an instrument well calculated, with some slight alterations, to 
_ produce the results you desire. 
_ “It possesses a compensation for temperature ; -besides which, it will be 
_ placed, when finally in action, in a room where the daily range of tempera- 
i ture is not more than half a degree Fahrenheit. 
«This instrument is not yet, however, in working order, and two months 
may perhaps elapse before it is quite ready. As you seem to think it de- 
sirable to obtain occasionally curves on an enlarged scale, it will be matter for 
_ our consideration whether this can be managed, and how. You will be duly 
informed of our resolution; but, in the mean time, I may state that it 
would be somewhat more than two months before such additional curves 
could be ready. In conclusion, without binding ourselves to any specified 
time (which, indeed, would not be desirable in a matter of this nature), I beg 
_ to assure you that we shall do all in our power to hasten the desired result ; 
and, as we hope to have things ready in the course of two or three months, 
7 * Secchi and Palmieri, 1862. 3 
¢ 
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