
REPORT OF THE COMMITTEE ON THE KEW OBSERVATORY. XXXIX 
Report of the Committee, consisting of Professor Wuratstone, Mr. 
Hutton, and the General Secretaries and Treasurer, appointed by 
the Council to superintend the establishment of Meteorological Obser- 
vations at the Kew Observatory. 
THE limited funds at the disposal of the Committee have not allowed them 
to carry many of the contemplated objects into effect. The preliminary ar- 
rangements have however been completed, and a very perfect and efticient 
apparatus for making observations on the electricity of the atmosphere has 
been established. ‘The Committee has paid more immediate attention to 
this subject on account of its importance in connexion with the system of 
simultaneous magnetic and meteorological observations now making on 
various points of the earth’s surface, in the recommendation of which the 
Association has taken so prominent a part. Hitherto electrical phenomena 
have been little attended to at these observatories, from the want of knowing 
what instruments to recommend for the purpose, and how to interpret pro- 
perly their indications. This want the Committee has every reason to be- 
lieve will shortly be supplied and arrangements be made for recording the 
electrical changes of the atmosphere at the various stations with the same 
regularity and accuracy as the other meteorological phenomena. 
The following is a brief notice of the present arrangements. 
The dome in which the Equatorial was formerly placed, has been convert- 
ed into the Electrical Observatory. A circular pedestal about eight feet in 
height is firmly fixed in the middle of the room, and a platform, which is as- 
cended by a few steps, surrounds the pedestal, so that the operator standing 
upon it shall be at a convenient height to adjust and observe the various in- 
struments. At the centre of the pedestal is fixed a strong glass pillar sup- 
porting a vertical copper tube tapering upwards ; the length of this conductor 
is twenty feet, sixteen feet being elevated above the dome in the open air. 
The lower part of the conductor within the dome carries four horizontal 
branches placed at right angles to each other; these are for the purpose of 
bringing into connexion with the conductor the various electrometrical in- 
struments employed. ‘The electricity of the atmosphere is collected by 
means of the flame of a lamp kept constantly alight during night and day, 
and placed at the upper extremity of the conductor ; by this plan, which Volta 
recommended, much more electricity is collected than by means of a metallic 
point; the lamp is lowered and elevated when required by means of a cord 
and pulley contained within the tube. 
The insulation of the conductor is preserved by the effective method pro- 
posed by Mr. Ronalds. The insulating glass support has in its interior a 
hollow conical space the base of which opens into the pedestal; beneath this 
opening is placed a small night-lamp, which heats the air within the cone and 
raises the temperature of the glass pillar. The upper part of the external 
surface of this pillar is not sufficiently heated to prevent the deposition of 
moisture, and is therefore, to a certain degree, a conductor; the lower part 
also conducts slightly on account of its elevated temperature; but there is a 
zone between these two parts which insulates perfectly on account of the tem- 
perature of that part of the surface being sufficient to expel all moisture and 
yet not sufficient to enable it to conduct. A conductor thus insulated will 
retain its charge for hours together without sensible diminution. — 
Another peculiarity and advantage of this method of insulation is, that the 
active parts of all the electrometers are suspended from the conductor, and 
are therefore uniformly charged, depending for their insulation we “. warmed 
