METEOROLOGICAL OBSERVATIONS AT CHISVVICK. 
53 
Months. 
Year 1870. 
Year 1871. 
Rain in inches. 
Days. 
Rain in inches. 
Days. 
January- 
3-64 
12 
February 
3-64 
12 
March 
... 
6-04 
23 
April 
1 i oo 
iO 
May 
10 41 
28 
8 17 
29 
J UI16 
8-32 
21 
5-61 
18 
July 
9.06 
25 
4-21 
17 
August 
10-85 
25 
4-50 
17 
September 
6-76 
19 
October 
7-10 
23 
November 
6-97 
22 
December 
3-21 
13 
Total rainfall during the year 1870, May 1st, to 1871, May 1st, 
85*58 inches, which fell on 246 days. 
XVI. Meteorological Observations taken at the Royal Horticul- 
tural Society's Gardens, Chiswick by W. Spinks. Eeduced 
by R. Steachan, Meteorological Oflice. 
The readings of the barometers and thermometers 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- 
oast; 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. 
