Meteorological Observations taken at Edinburgh. 77 
Complete copies of the observations taken have been 
supplied monthly to the Scottish Meteorological Society, 
and the Meteorological Office, London, and weekly returns 
of temperature and rainfall to the Registrar-General, 
similar weekly returns of bright sunshine being sent to 
the Meteorological Office. Monthly and yearly rainfall 
reports are supplied to Mr Symons for his annual work on 
British Rainfall. The instruments in use are as follows :— 
Barometers—The standard barometer is a Kew marine, 
which has a tube 0°5 inch in diameter, and is read by 
means of a vernier directly to 0-002 inch. Another 
barometer of the same description is kept as a reserve 
instrument. Continuous traces of pressure oscillations are 
furnished by two barographs, one a mercurial instrument 
by Redier of Paris, the other being one of the well-known 
Richard aneroids. One of the Watkin patent aneroid 
barometers is also kept as a reserve instrument. For an 
aneroid it is remarkably accurate. 
Thermometers and Hygrometers.—These are exposed in a 
double louvred Stevenson screen, at a height of 4 feet 
above grass, and consist of maximum and minimum register- 
ing thermometers and a Mason’s hygrometer. Duplicates of 
these instruments are kept in reserve. A thermograph, by 
Richard Brothers of Paris, gives a continuous record of 
temperature fluctuations, corresponding values of relative 
humidity being obtained from a hygrograph by the same 
makers. 
Radiation Thermometers——For the registration of solar 
radiation, a maximum thermometer in vacuo, with the bulb 
and part of the stem blackened, is employed. The difference 
between the indications of a registering minimum ther- 
mometer freely exposed on the surface of the grass, and 
a similar thermometer in the shade 4 feet above it, gives 
a measure of the intensity of terrestrial radiation. 
‘Rain Gauges—Two of these are in use, the standard being 
a copper cylinder, 14 inches deep, with a turned brass rim 
5 inches in diameter. One of Symon’s storm rain gauges 
is in use from April to October for the direct observation of 
thunderstorm and other torrential rains. 
