120 
ROYAL nORTICULTURAL SOCIETY. 
XXIII. Meteorological Observations taken at the Royal Horticul- 
tural Society's Gardens, Chiswick, by W. Spinks. Reduced 
by R. Strachan, Meteorological Office. 
The readings of the barometer and thermometer are all corrected 
for instrumental errors (which have been ascertained at the Kew 
Observatory), and those of the barometer are reduced to the tem- 
perature of 32° Fah., and to mean sea-level. 
The rain gauge is 25 feet above sea-level. 
The temperature of evaporation is regularly observed, but is not 
given here. It has been considered preferable to give the dew- 
point, which has been calculated from this observation by means of 
Glaisher's factors. 
The figures denoting the estimated force of the wind signify as 
follows: — 1, light air; 2, light breeze; 3, gentle breeze ; 4, mode- 
rate breeze ; 5, fresh breeze ; 6, strong breeze ; 7, moderate gale ; 
8, fresh gale; 9, strong gale; 10, whole gale; 11, storm; 12, 
hurricane. 
The notations of weather are, for brevity, expressed by letters, 
which signify as follows : — b, blue sky ; c, detached clouds ; o, over- 
cast ; f, fog ; m, mist ; r, rain ; h, hail ; s, snow ; d, drizzle ; 
p, passing showers ; q, squalls ; t, thunder ; 1, lightning. A letter 
repeated denotes intensity. 
[A reduction of these observations has been published by Mr. 
Glaisher in the Registrar-General's Report, but the results given 
by him are different, probably owing to the corrections not being 
applied to each observation, but to the monthly means. — Eds.] 
