36 
Looking over the numbers in these Tables we see that in any monti 1 
the range may be as small as 1° to 5°, and as large as from 30° to 4C;| 
in the winter months, and exceeding 40° by several degrees in tb t 
summer months. That frequently several days of small range corr : l 
together, indicative of so many days of cloudy skies ; and several daj j 
of larger range come together, indicating periods of clear skies. 
By looking at the numbers on the same horizontal line, or the daill 
ranges of temperature on the same day of the month in different yearl 
similar large differences appear ; for instance on January 1 in the yeJ 
1837 the range was 23°, whilst in 1851 and 1859 on the same day 1 
the year it was 3° only. Great varieties are thus shown on every day t| 
comparing the results of different years together, or the numbers cl 
the same horizontal line in the several Tables. 
These results, being dependent on the different directions of the win- 
the more or less cloudy state of the sky, and the different conditions i 
the weather generally, are as variable as the weather itself. 
The maximum and minimum temperatures from which these resul 
have been obtained are not given in these series of Tables, but tlnj 
may be found approximately on any day by adding one-half of tl 
range to the mean temperature of the same day, Table I. to XII., f< 
the maximum, and by subtracting one-half of the range from til 
mean temperature for the day for the minimum. 
By selecting the smallest and largest range in each month in all tl 
years Table XLII. has been formed. 
This Table shows very clearly how variable the range of temperatui 
may be in twenty-four hours, and how very different in different yeail 
For instance, in the month of January under 1 greatest ’ in the ye I 
1833, the largest range inany one day was 15°, whilstin general it exceei 
20°, and in some years it has been as large as 30°. On the contra J 
under ‘ least ’ in the years 1828 and 1854 the range has been as sm;l 
as 1°, and by looking down the column it will be seen that ranges I 
small as 2° or 3° are common, whilst in other years there has been p 
range less than 8° or 9°. As small daily ranges have taken place i 
J anuary and December, as 1° ; in February and November as 2°; i 
March, April, and October as 3°, in June and September as 4° ; al 
in July and August as 5°. As large daily ranges as 32° have taka 
place in the months of January and December ; of 34° in November 
of 38° in February; of 39° in March ; of 42° in June and October; 1 
44° in May ; of 45° in July ; of 48° in April, and one of 49° in Augit 
1861, which is the largest in the Table. 
By taking the mean of all the daily ranges in each year, or the me a 
of the numbers in every vertical column in Tables XXX. to XI., 
Table XLIII. is formed. 
From these numbers we see that the mean monthly daily range If 
temperature has varied 
