I5Q ON THE PERIODIC AND NON-PERIODIC VARIATIONS 
With a view of assisting the inquiry whether non-periodic variations of a uniform 
character manifest a tendency to recur at the same epochs in different years, the 
daily averages in column 14 of Table IV. have been collected in Table V. into 
“five-day means,” each of the five-day means thus represented being the a^eiage 
non-periodic variation in those five-days in twelve years. And for the purpose of 
supplying a more satisfactory indication of the degree of variability to which the 
temperature of any single day is subject at different seasons, than can be obtained 
by the mere inspection of the differences in columns 2 to 13 of Table IV., the 
“ probable daily non-periodic variation” in column 3 of Table V. has been computed 
for each of the five-day periods, upon the same principle and by the same process 
that the “probable error” of each of several partial results is derived from their 
mutual differences ; whilst in column 2 is shown the probable non-periodic variation 
corresponding to the averages of five days in twelve years contained in column 1, 
bearing a similar analogy to the probable error of the arithmetical mean of a senes 
of partial results. 
Table V. 
Five-day periods. t 
i 
Non-peri- 
odic varia- 
tions in 
welve years 
iveraged in 
five-day 
means. 
Probable 
non-peri- 
odic varia- 
tion in the 
averages of 
five days in 
Column 1. 
Probable 
daily 
non-peri- 
odic varia- 
tion. 
Five-day periods. 1 
Non-peri- 
odic varia- 
tions in 
welve years 
iveraged in 
five-day i 
means. | 
Probable 
non-peri- 
odic varia- 
tion in the 
averages of 
five days in 
Column 1. 
Probable 
daily 
non-peri- 
odic ^■a^ia- 
tion. 
Jan. 3 to 7 inclusive. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to Feb. 1. 
Feb. 2 to 6. 
7 to 11. 
12 to 16 . 
17 to 21. 
22 to 26 . 
27 to March 3. 
Mar. 4 to 8. 
9 to 13. 
14 to 18. 
19 to 23. 
24 to 28. 
29 to April 2. 
Apr. 3 to 7. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to May 2. 
May 3 to 7. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to June 2. 
June 3 to 7- 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to July 2. 
(!•) 
-0-7 
— 1-1 
-f 2-0 
. —2-8 
-1-2-0 
-0-7 
-I-1-6 
-1-6 
-2-9 
-l-l-O 
-f 1-5 
— 1*4 
-I-2-0 
-bF8 
-1-8 
-0*9 
+ 0-9 
-0-6 
-hO-6 
-0-1 
-1*7 
-pO-2 
+ 0-5 
-0-2 
— 0-5 
-f-M 
-i-1-0 
— 1-3 
4-0-3 
-1-2 
— 0-8 
-1-9 
-0-5 
-i-1-9 
-f 1-3 
+ 0-3 
(2.) 
±0-8 
±0-9 
±0-8 
±M 
±0-9 
±1-0 
±0*8 
±0-9 
±0-9 
±1-0 
±0-9 
+ 0*8 
+ 0-7 
±0-6 
+ 0-8 
±0-7 
+ 0’6 
+ 0-7 
±0-6 
+ 0-7 
±0-6 
+ 0’6 
+ 0-6 
±0-5 
+ 0‘6 
+ 0-5 
+ 0-6 
+ 0-6 
-f 0-6 
+ 0-6 
4-0-6 
+ 0-7 
4-0-6 
4-0-5 
4-0-4 
4-0-4 
(3.) 
±5-8 
+ 6-2 
±6-1 
±7-7 
±6-7 
±7-3 
±6-0 
±6-3 
±6-7 
+ 7-0 
±6-9 
±5-8 
+ 5-0 
+ 4-6 
4-5-6 
±5-0 
4-4-5 
4-5-3 
4-4-0 
4-4-7 
4-4-6 
4-4-4 
4-4-2 
4-4-0 
4-4-3 
4-3-9 
4-4-0 
+ 4-3 
+ 4-3 
+ 4-6 
+ 4-4 
+ 5-0 
+ 4-6 
+ 3-6 
+ 3-1 
+ 3-5 
July 3 to 7 inclusive. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to Aug. 2. 
Aug. 3 to 7. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to Sept. 2. 
Sept. 3 to 7. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to Oct. 2. 
Oct. 3 to 7. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to Nov. 2. 
Nov. 3 to 7. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 27. 
28 to Dec. 2. 
Dec. 3 to 7. 
8 to 12. 
13 to 17. 
18 to 22. 
23 to 28. 
29 to Jan. 2. 
(1-) 1 
O 
— 1-5 
+ 1-8 
+ 1-1 
+ 1-4 
-0-9 
-2-7 
0-0 
+ 0-2 
0-0 
-0-7 
0-0 
+ 2-3 
+ 1-6 
+ 0-3 
-1-8 
+ 0-3 
-1-6 
-0-5 
+ 1-5 
+ 2-9 
— 1-3 
-1-7 
-1-6 
+ 1-0 
+ 0-5 
— 0-1 
+ 0-8 
+ 0-7 
— 0-9 
— 2-1 
+ 1*7 
+ 0-9 
-0-8 
— .3-2 
-0-7 
+ 2-4 
(2.) 
±6-5 
±0-6 
±0-5 
±0-4 
±0-4 
±0-5 
±0-4 
±0-4 
±0-4 
±0-4 
±0-4 
+ 0-5 
±0-5 
±0*7 
+ 0-6 
+ 0-6 
+ 0-6 
+ 0-5 
+ 0-5 
+ 0-5 
j +0-5 
! ±0-5 
+ 0-5 
i +0-6 
! +0-6 
+ 0-6 
+ 0-5 
+ 0-6 
+ 0-7 
+ 0-7 
+ 0-6 
+ 0-8 
+ 0-8 
+ 0-8 
+ 0-9 
+ 0-8 
(3.) 
±3-4 
±4-2 
±3-5 
±3*1 
±3-0 
±3-7 
±2*6 
±2*8 
±3-0 
±2-7 
±3-3 
±3-6 
±3*4 
±4-7 
±4-3 
±4-2 
+ 4-4 
±3-7 
±3-6 
± 3-9 
±3-9 
+ 3-9 
+ 3-9 
+ 4-9 
+ 4-3 
+ 4-1 
! +3-6 
+ 4-2 
+ 4-9 
+ 5-3 
+ 4-4 
±5-5 
+ 5-8 
+ 6-0 
+ 5-8 
+ 6-1 
