OF TEMPERATURE AT TORONTO IN CANADA, 
143 
same system was preserved in respect to days, but the hours of observation were less 
frequent. The series may consequently be divided into two portions, of which the 
first, or that containing- the six years of hourly observation, will be first discussed. 
The following Table exhibits the mean temperature at every hour in the different 
months on the average of the six years. 
Table I. 
Mean Temperature of the Air at Toronto, obtained by hourly observations from 
July 1, 1842 to June 30, 1848. 
Toronto 
astrono- 
mical time. 
Months. 
Hourly 
means. 
Jan. 
Teb. 
March. 
April. 
May. 
June 1 
July. 
August. 
Sept. 
October. 
Nov. 
Dec. 
Hours. 
0 
0 
0 
0 
0 
0, 
2^83 
2^07 
34-00 
47-53 
58-80 
66*55 
72-85 
72-30 
63-52 
49-50 
39*57 
29-93 
49*12 
1. 
28-33 
27-93 
34-65 
48-47 
59-72 
67-28 
73-77 
73-07 
64-12 
49*93 
39-97 
30-65 
49-82 
2. 
28-60 
28-33 
35-22 
48-85 
60-07 
67-70 
74-62 
73-65 
64-52 
50-28 
40-05 
30-80 
50-22 
3. 
28-57 
28-32 
35-02 
48-92 
60-13 
68-08 
74-82 
74-00 
64-55 
50-05 
39-88 
30-55 
50-24 
4. 
28-05 
27-77 
34-55 
48-53 
60-08 
68-32 
74-83 
73-85 
64-33 
49-32 
38‘98 
29*90 
49*88 
5. 
27*05 
26-57 
33-80 
47-80 
59-70 
67-72 
74-37 
73-30 
63-37 
47*57 
37-77 
28-95 
49*00 
6. 
26-23 
25-12 
32-12 
46-00 
57-95 
66-42 
72-93 
71*40 
60-70 
45*52 
36-95 
28-25 
47.47 
7. 
25-70 
24-13 
30-65 
43-47 
55-08 
63-68 
69*45 
67*42 
58-00 
44-42 
36-38 
27-92 
45-52 
8. 
25-38 
23-28 
29-68 
41-88 
52-37 
60-38 
65-25 
64-50 
56-72 
43-68 
36-07 
27*53 
43*89 
9. 
25-18 
22-63 
28-68 
40-80 
50-62 
58-22 
62-88 
62-92 
55-68 
42-92 
35-78 
27*28 
42-80 
10. 
24-80 
22-08 
28-03 
40-03 
49-65 
56-88 
61-65 
61-90 
54-62 
42-17 
35-43 
26-98 
42-02 
11, 
24-48 
21-57 
27-38 
39-53 
48-73 
55-92 
60-47 
61-10 
53-98 
41-50 
35-08 
26-87 
41-38 
12. 
23-80 
21-45 
27-33 
39-37 
47-88 
55-37 
59-45 
60-30 
53-63 
40-95 
34-42 
26-53 
40-87 
13. 
23-33 
21-07 
26-85 
38-62 
47-02 
54-68 
58-58 
59*65 
53-02 
40-35 
34-13 
25-95 
40-27 
14. 
23-25 
20-73 
26-47 
37-95 
46*18 
53-98 
58-02 
58*97 
52-43 
40-03 
33-85 
25-58 
39*79 
15. 
23-10 
20-30 
26-18 
37-75 
45-47 
53-20 
57*30 
58-30 
51-97 
39-87 
33-53 
25-45 
39*37 
16. 
23-00 
20-00 
25-80 
37-32 
45-00 
52-63 
56-67 
57*92 
51-38 
39-57 
33-37 
25-42 
39-01 
17. 
22-82 
19-65 
25-28 
36-95 
45-05 
52-82 
56-62 
57-73 
50-75 
39-40 
33-48 
25-40 
38-83 
18. 
23-55 
19-08 
25-00 
37-08 
47-50 
55-47 
59*83 
59*18 
51-43 
39*62 
33-75 
24-98 
39*71 
19. 
23-45 
18-95 
25-87 
39-37 
50-48 
58-28 
63*50 
62-15 
53-98 
40-37 
33-75 
24-82 
41-25 
20. 
23-68 
19-97 
27-85 
41-62 
52-70 
60-62 
66-10 
65-42 
56-73 
42*62 
34-80 
25-25 
43-11 
21. 
24-65 
22-27 
30-02 
43-60 
55-02 
62-50 
68-30 
67-92 
59-15 
45-30 
36-33 
26-43 
45-12 
22. 
25-88 
24-28 
31-75 
45-12 
56-72 
64-17 
70-00 
69-90 
61-12 
47-23 
37*77 
27-88 
46-82 
23. 
27-05 
25-87 
32-98 
46-50 
57*85 
65*45 
71-55 
71-35 
62-55 
48-60 
38-78 
29-12 
48-14 
Monthly \ 
means. [ 
25-32 
23-27 
29-80 
42-63 
52-91 
t 
60*68 
65-99 
65-76 
57*59 
44-20 
36-24 
27*44 
44-32 j 
The hourly observations from which this Table is formed will be found in full 
in the volumes of the Magnetical and Meteorological Observations at the British 
Colonial Obervatories, of which Toronto was one. 
The temperature at any hour, and on any day of the year, corresponding to the 
mean values obtained in the six years and shown in Table I., may be computed from 
them by means of Bessel’s well-known interpolation-formula*, which may be thus 
w-ritten for the purpose : — 
C=Ao+A, cos a-f-BiSin a-l-A 2 COs 2 a-(-B 2 sin 2 a 
+ A 3 cos 3a-}- Bg sin 3a-l- A 4 cos 4 a-|-B 4 sin 4a 
-j-Ag cos Sa-j-Bj sin 5a-}- Ag cos 6 a, 
* Astron. Nach. No. 136. 
