264 
POPULAR SCIENCE REVIEW. 
Eventually so much of this “ Explanation ” as could be so 
placed, was prefixed to the columns in the daily tables : hence 
their present form differs somewhat from the above, and they 
have become more convenient for perusal. 
The plan upon which the meteorological information is 
reported to head-quarters from the several stations may be thus 
epitomised. Each telegram consists of five or six groups of figures 
(each group containing five figures) and occasionally a few words. 
No alterations or reductions are made by the observer who 
transmits them as they are read off, except in a few special 
cases. The reductions are performed in London with the aid of 
data, furnished as occasion may require, by the several observers. 
The first group is Eainfall (R.) omitting decimal points. With 
each morning report, when rain enough has fallen to be 
measurable, its duration in hours from 1 to 24 (or to 48 after 
a Sunday or holiday) occupies the first two places of a 5-figure 
group, a cypher being prefixed before 1 to 9: quantity of rain 
(snow &c. melted) is shown by the last three figures of the five as 
inches and hundredths. Thus if rain has prevailed for four hours 
since the previous report and half an inch is the gauge, the 
group will be 04050; if for fifteen hours with one inch and 
three quarters, the group will be 15175. 
The second group of figures shows the highest or lowest 
extreme (the most remarkable) of the mercury in the barometer 
(B) and in the exposed thermometer (E) since the previous 
report by telegraph. B occupies the three first places of the 
group for the last integer and two first decimals ; and 2 the two 
final figures for whole degrees of the exposed dry thermometer. 
Thus if the extreme reading of the barometer has been 30T29, 
and that of the thermometer 54*3 the group for the telegram 
will be 01354, the reading of the barometer being in all cases 
taken to the nearest hundredth and of the thermometer to the 
nearest whole degree. 
The third group of five figures is devoted to the height of the 
barometer and of the attached thermometer at the regular 
observing hour be it 8 A.M. for a morning telegram, or 2 
p.M. for an afternoon one, the method of enunciating which 
will be understood from the last paragraph. 
The fourth group expresses the extreme, not simply the general 
character of the wind and weather (D F I) since the last report. 
The first two figures are allotted to the direction of the wind (D) 
the third and fourth to the force (F) and the last figure to the 
character of the weather. The direction of the wind is repre- 
sented by figures 1 to 32, one for each point of the compass 
from N. round by E. S. and W. to N. again. North being 32, East 
8, South 16, and West 24, and so proportionally for the interme- 
diate points. A cypher preceding the points numbered below 10 
