METEOROLOGY 
17 2 
to m. From this last equation the value of 
n is forfnd to be 53 nearly ; and in is nearly 
equal to 84. The mean temperature of the 
equator, therefore, is 84°, and that of the pole 
3 1°. To find the mean temperature for every 
other latitude, we have only to find 88 arith- 
metical means between 84 and 31. I 11 this 
manner Mr. Kirwan calculated the following 
table: 
TABLE 
Of the Mean Annual Temperature of the 
Standard Situation in every Latitude. 
Lat. 
Temper. 
Lat. 
Temper. 
Lat. 
Temper. 
90 
31. 
71 
3 6.6 
52 
51.1 
89 
31.04 
70 
37.2 
51 
52.4 ' 
88 
SI. 10 
69 
37.8 
50 
52.9 
87 
31.14 
68 
38.4 
49 
53.8 
86 
31.2 
67 
39.1 
48 
54.7 
85 
31.4 
66 
39.7 
47 
55.6 
84 
31.5 
65 
40.4 
46 
56.4 
83 
31.7 
64 
41.2 
45 
57.5 
82 
32. 
63 
41.9 
, 44 
58.4 
81 
32.2 
62 
42.7 
43 
59.4 
80 
32.6 
61 
43.5 
' 42 
60.3 
79 
32.9 
do 
44.3 
41 
61.2 
78 
33.2 
59 
45.09 
40 
62. 
77 
33.7 
58 
45.8 
39 
63. 
76 
34.1 
57 
46.7 
38 
63.9 
75 
34.5 
56 
47.5 
37 
64.8 
74 
35. 1 
55 
48.4 
36 
65.7 
73 
35.5 
54 
49.2 
35 
66.6 
72 
36. 1 
53 1 
50.2 1 
34 
67.4 
Lat. 
Temper. 
Lat. 
Temper. 
Lat. 
Temper. 
33 
68.3 
23 
75.9 
13 
81 3 
32 
69.1 
OO 
76.5 
12 
81.7 
31 
69.9 
21 
77.2 
11 
82. 
30 
70.7 
20 
77.8 
iO .. 
82.3 
29 
71.5 
19 
78.3 
| 9 
82.7 
28 
72.3 
IS 
78.9 
! 8 
82 9 
27 
72.8 
17 
79.4 
! 7 
83.2 
26 
73.8 
16 
79.9 
6 
83.4 
L 25 
74.5 
15 
80.4 
5 
83. G 
24 
75.4 
14 
80.8 
0 
84. 
This table, however, only answers for the 
temperature of the atmosphere of the ocean. 
It was calculated for that part of the Atlantic 
Ocean which lies between the 80th degree 
of northern and the 45th of southern latitude, 
and extends westward as far as the Gulf- 
stream, and to within a few leagues of the 
coast of America ; anil for ail that part of the 
Pacific Ocean reaching from latitude 45® 
north to latitude,40° south, from the 20th to 
the 275th degree of longitude east of Lon- 
don. This part oi the ocean Mr. Kirwan calls 
the standard; the rest of the ocean is subject 
to anomalies which will he afterwards men- 
tioned. 
Mr. Kirwan has also calculated the mean 
monthly temperature of the standard ocean. 
The principles on which he went were these: 
The mean temperature of April seems to ap- 
proach very nearly to the mean annual tem- 
perature ; and as far as he3t depends on the 
action of the solar rays, the mean heat of 
every month is as the mean altitude of the 
sun, or rather as the sine at the sun’s altitude. 
The mean heat of April, therefore, and the 
sure of rhe sun’s altitude, being given, the. 
mean heat of May is louncl in tins manner: 
As the sine of the sun’s mean altitude in 
April, is to the mean heat ot April, so is the 
sine of the sun’s mean altitude in May, to the. 
mean heat of May. In the same maim, r 
the mean heats of June, July, and August 
are found; hut the rule would give the Tem- 
perature of the succeeding months too low 
because it does not take in the heat derived 
from the earth, which possesses a degree of 
heat nearly equal to the mean annual tempe- 
rature. The real temperature of. these 
months, therefore, must be looked upon as 
an arithmetical mean between the astrono- 
mical and terrestrial heats. Thus, in latitude • 
51°, the astronomical heat of the month of 
September is 44 6°, and the mean annual heat, 
is 52.4° ; therefore the real-heat of tins month 
44 6 _L 52 4 
should be — — _ 43 . 5 . Mr. Kirwan, , 
however, after going through a tedious cal- 
culation, found the results to agree so ill with 
observati®ns, that he drew up the following 
table, partly from principles, and partly by 
studying a variety of sea journals: 
TABLE of the Monthly Mean Temperature of the Standard from Lat. 80° to Lat. 10°. 
Lat. 
80° 
79° 
[ 78° 
77° 
76° 
75° 
740 
73° 
72° 
71° 
70° 
69° 
68° 
67° 
66° 
65® 
64° 
63* 
January 
22. 
22.5 
23. 
23.5 
24. 
24.5 
25. 
25.5 
26. 
26.5 
27. 
27.5 
27.5 
28. 
28. 
28. 
29. 
*30 
February 
23. 
23. 
23.5 
24. 
24.5 
25. 
25.5 
26. 
26.5 
27. 
27.5 
28. 
28. 
28.5 
29. 
30. 
31. 
32. 
March 
27. 
27.5 
28. 
28.5 
29. 
29.5 
30. 
30.5 
31. 
31.5 
T32. 
32.5 
S3. 
33.5 
34. 
35. 
36. 
37. 
Aprd 
32.6 
32.9 
33.2 
33.7 
34.1 
34.5 
35. 
35.5 
36. 
36.6 
37.2 
37.8 
38.4 
39.1 
39.7 
40.4 
41.2 
41.9 
May 
36.5 
36.5 
37. 
37.5 
38. 
38.5 
39. 
39.5 
40. 
40.5 
41. 
41.5 
42. 
425 
43. 
44. 
45. 
46. 
June 
51. 
51. 
51.5 
52. 
52. 
52. 
52.5 
53. 
53.5 
54. 
54. 
54.5 
54.5 
54.5 
55. 
55. 
55.5 
55.5 
July 
50. 
50. 
50.5 
51. 
51. 
51. 
51.5 
52. 
52.5 
53. 
53.5 
53.5 
53.5 
54. 
54.5 
54.5 
55. 
55. 
August 
39.5 
40. 
41. 
41.5 
42. 
42.5 
43. 
43.5 
44. 
44.5 
45. 
45.5 
46. 
47. 
48. 
48.5 
49. 
50. 
September 
33.5 
34. 
34.5 
35. • 
35.5 
36. 
S6.5 
37. 
38. 
38.5 
39. 
39.5 
40. 
41. 
42. 
43. 
44. 
45. 
October 
28.5 
29. 
29.5 
30. 
30.5 
31. 
31.5 
32. 
32.5 
33. 
33.5 
34. 
34. 
35. 
36. 
37. 
37.5 
38. 
.November 
23. 
23.5 
24. 
24.5 
25. 
25.5 
26. 
26.5 
27. 
27.5 
28. 
28.5 
29. 
30. 
31. 
32. 
32.5 
33. 
December 
22.5 
23. 
23.5 
24. 
24.5 
25. 
25.5 
26. 
26.5 
27. 
27.5 
28. 
28. 
29. 
SO. 
30.5 
SI. 
31. 
Lat. 
62° 
61° 
60° 
59° 
00 
57® 
56° 
55° 
! - 
! 
53° 
52° 
51° 
50° 
49® 
48° 
47° 
46° 
45* 
January 
31. 
32. 
33. 
34. 
35. 
36. 
37. 
38. 
39. 
40. 
41. 
42. 
42.5 
43.5 
43. 
42.5 
44. 
44.5 . 
February 
33. 
34. 
35. 
36. 
37. 
38. 
39. 
40. 
41. 
42. 
43. 
44. 
44.5 
44.5 
45. 
45.5 
46. 
46.5 
March 
38. 
39. 
40. 
41. 
42. 
43. 
44.6 
45. 
46. 
48. 
49. 
50. 
50.5 
51. 
52.5 
53. 
53.5 
54.5 
April 
42.7 
43.5 
44.3 
45.09 
45.8 
46.7 
47.5 
48.4 
49.2 
50.2 
51.1 
52.4 
52.9 
53.8 
54.7 
55.6 
56.4 
57.5 
May 
47. 
48. 
49. 
50. 
51. 
52. 
53. 
54. 
55. 
56. 
57. 
58. 
58.5 • 
59. 
60. 
61. 
62. 
63. 
June 
56. 
56. 
56. 
56.5 
57. 
57. 
57.5 
58. 
58.5 
59. 
59. ~ 
60. 
61. 
62. 
63. 
64. 
65. 
66. 
July 
55.5 
55.5 
56. 
56.5 
57. 
57.5 
58. 
59. 
60. 
61. 
62. 
63. 
63.5 
64. 
65. 
66. 
67. 
68. 
August 
51. 
52. 
5.3. 
54. 
55. 
56. 
57. 
58. 
59. 
60. 
61. 
62. 
63.5 
64. 
65. 
66. 
67. 
68. 
September 
46. 
47. 
48. 
49. 
50. 
51. 
52. 
53. 
54. 
55. 
56. 
57. 
58.5 
59. 
60. 
61. 
62. 
63. 
October 
39. 
40. 
41. 
42. 
43. 
44. 
45. 
46. 
47. 
48. 
49. 
50. 
50.5 
51. 
52. 
53. 
54. 
55. . 
November 
34. 
35. 
'36. 
■37. 
88. 
39. 
40. 
41. 
42. 
43. 
44.5 
46. 
4 6.5 
47. 
48. 
49. 
50. 
51. 
December 
32. 
33. 
34. 
35. 
36. 
37. 
38. 
39. 
40. 
41. 
42. 
44. 
44.5 
45. 
46. 
47. 
48. 
49. 
Lat. 
44° 
43° 
42° 
41° 
40° 
39® 
38° 
37® 
36® 
CO 
1 0 
34° 
33° 
32° 
31° 
30° 
29° 
28° 
27* 
January 
45. 
45.5 
46, 
46.5 
49.5 
51. 
52. 
53.5 
55. 
56.5 
59.5 
63. 
63. 
63. 
-63.5 
63.5 
63.5 
64. 
February 
47. 
48. 
49. 
50. 
53. 
56.5 
58. 
60. 
61. 
62. 
63. 
64.5 
66. 
67. 
68.5 
68.5 
69.5 
69.5 
March 
55.5 
56.5 
58.5 
59.5 
60. 
60.5 
61. 
62. 
63. 
64. 
65. 
66.5 
67.5 
68.5 
69.5 
71. 
72. 
72.5 
April 
58.4 
59.4 
60.3 
61.2 
62.1 
63. 
63.9 
64.8 
65.7 
66.6 
6 7.4 
68.3 
69.1 
69.9 
70.7 . 
71.5 
72.3 
72.8 
May 
64. 
65. 
66. 
67. 
68. 
69. 
70. 
70.5 
71. 
71.5 
72. 
72.5 
73. 
73. 
73.5 
74.5 
7 5.5 
76. 
June 
67. 
68. 
69. 
70.- 
70.5 
71. 
71. 
71. 
71.5 
71.5 
72. 
72.5 
73. 
73. 
73.5 
74.5 
75.5 
76. 
July 
69. 
69.5 
70. 
70. 
71. 
71. 
72. 
72. 
72.5 
72.5 
72.5 
72.5 
73. 
73. 
73.5 
74.5 
75.5 
76. 
August 
69. 
69.5 
70. 
70. 
71. 
71. 
72. 
72. 
72.5 
72.5 
72.5 
72.5 
73. 
73. 
73.5 
74.5 
75.5 
76. 
September 
64. 
66. 
68. 
69.5 
70.5 
71. 
71.5 
72. 
72.5 
72.5 
72.5 
72.5 
73. 
73. 
73.5 
74. 
75.5 
76. 
October 
56. 
57 . 
53. 
59. 
60. 
61. 
62. 
63. 
64. 
65. 
66. 
67.5 
68.5 
69.5 
70.5 
71. 
72.5 
72.5 
November 
52. 
53. 
54. 
55. 
56. 
57. 
58. 
59. 
60. 
61. 
62. 
63. 
64.5 
65.5 
66.5 
68. 
69. 
69.5 
December 
50. 
51. 
52. 
53 . 
54. 
55 . 
56. 
51% 
58. 
59. 
60. 
61. 
62.5 
62.5 
64.5 
66. 
67. 
67.5 
