xx REPORT—1850. 
from the Committee the subjoined Report on the present state and pro- 
spects of the Observatory. 
Report of the Kew Committee—“ The grant made by the General Com- 
mittee for maintaining the establishment at Kew Observatury during the 
present year being in a considerable degree founded on the results actually 
secured, and others likely to be obtained by the electrical observations which 
have been instituted there, the Committee for superintending the Observatory 
have kept the prosecution and extension of these experiments steadily in view. 
“ Ever since 1843 a series of measures of the intensity of atmospheric elec- 
tricity has been accumulated at Kew. By direction of the General Com- 
mittee in 1848, Mr. Birt was engaged on the discussion of these, and his 
Report is published in the Transactions of the Association for 1849. By 
this investigation the seeming irregularity of these phenomena has been in 
some degree elucidated, and results having a general and systematic value 
obtained. For example, during the twenty-four hours the electrical tension 
of the atmosphere acquires two maxima, viz. about 10 A.M. and 10 P.M., and 
suffers two minima, viz. about 4 A.M. and 4 p.M., these being also nearly the 
hours of barometrical maxima and minima. Moreover, in the course of the 
twelve months, there is distinetly a periodicity of electrical tension ; the maxi- 
mum for the year being in the depth of winter, and the minimum in the 
height of summer. Mr. Birt has shown the relation of the curve which re- 
presents the annual movement of the electrical tension to that which describes 
the humidity of the air. 
* To the experiments from which these and other interesting relations have 
arisen, the Committee has been enabled to add a new series of observations 
on electrical frequency, by which not the intensity of the atmospheric charge, 
but the vate at which the instrument receives it will become known. These 
observations were begun under Mr. Ronalds’s direction in March 1850, and 
were continued for three weeks; but unfortunately the state of Mr. Birt’s 
health has not only stopped the observations, but deprived the Observatory 
of the further services of that gentleman. 
“The Committee will be able to supply the deficiency thus occasioned, 
and conduct these and other researches in a satisfactory manner, if the General 
Committee shall think fit to empower them, by the appointment of Mr. Welsh, 
late Assistant in the Observatory of Sir Thomas Brisbane, a gentleman of 
whose qualifications for the duties of Observer at Kew, the Committee have 
ample testimony. 
“Tn originally accepting the charge of this Observatory (1842), the Asso- 
ciation was influenced by the facilities which it would afford for the prosecu- 
tion of experimental inquiries in the physical sciences, for which its locality 
is peculiarly suitable, and at the close of the first year the Council had esta- 
blished the following registers in addition to the electrical observations al- 
ready noticed :— 
“An ordinary meteorological record with standard instruments; and had 
made arrangements with Professor Wheatstone for the completion of a self- 
registering meteorological instrument on a new construction. ; 
“ The advantage to be derived from self-recording instruments by meteo- 
rology and magnetism has been often expressed by votes of the Association 
from an early period of its career. The establishment of Kew Observatory 
brought these ideas into practical operation. That Observatory has given to 
science self-recording instruments for electrical, magnetical, and meteorolo- 
gical phenomena, already of great value, and certainly capable of great further 
improvement. Mr. Ronalds, whose valuable services have been given gra- 
tuitously to the Observatory from nearly its foundation, is still intent on im- 
Ba sets - Se 
