_t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_
(Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry
ther.)|18°.0|19°.0|20°.0|21°.0|22°.0|23°.0|24°.0|25°.0|26°.0|27°.0|28°.0|29°.0|30°.0|ther.)
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-------
55 | 6 | 1 | | | | | | | | | | | | 55
56 | 8 | 3 | | | | | | | | | | | | 56
57 | 9 | 5 | | | | | | | | | | | | 57
58 | 11 | 7 | 2 | | | | | | | | | | | 58
59 | 12 | 8 | 4 | | | | | | | | | | | 59
| | | | | | | | | | | | | |
60 | 14 | 10 | 6 | 2 | | | | | | | | | | 60
61 | 15 | 11 | 7 | 3 | | | | | | | | | | 61
62 | 16 | 13 | 9 | 5 | 1 | | | | | | | | | 62
63 | 18 | 14 | 10 | 7 | 3 | | | | | | | | | 63
64 | 19 | 15 | 12 | 8 | 5 | 1 | | | | | | | | 64
| | | | | | | | | | | | | |
65 | 20 | 17 | 13 | 10 | 6 | 3 | | | | | | | | 65
66 | 22 | 18 | 14 | 11 | 8 | 4 | 1 | | | | | | | 66
67 | 23 | 19 | 16 | 12 | 9 | 6 | 2 | | | | | | | 67
68 | 24 | 20 | 17 | 14 | 10 | 7 | 4 | 1 | | | | | | 68
69 | 25 | 22 | 18 | 15 | 12 | 8 | 5 | 2 | | | | | | 69
| | | | | | | | | | | | | |
70 | 26 | 23 | 19 | 16 | 13 | 10 | 7 | 4 | 1 | | | | | 70
71 | 27 | 24 | 20 | 17 | 14 | 11 | 8 | 5 | 2 | | | | | 71
72 | 28 | 24 | 22 | 18 | 15 | 12 | 9 | 6 | 3 | 1 | | | | 72
73 | 29 | 25 | 22 | 19 | 16 | 13 | 10 | 8 | 5 | 2 | | | | 73
74 | 30 | 26 | 23 | 20 | 18 | 15 | 12 | 9 | 6 | 3 | 1 | | | 74
| | | | | | | | | | | | | |
75 | 31 | 27 | 24 | 21 | 19 | 16 | 13 | 10 | 7 | 5 | 2 | | | 75
76 | 31 | 28 | 25 | 22 | 20 | 17 | 14 | 11 | 8 | 6 | 3 | 1 | | 76
77 | 32 | 29 | 26 | 23 | 20 | 18 | 15 | 12 | 10 | 7 | 4 | 2 | | 77
78 | 33 | 30 | 27 | 24 | 21 | 19 | 16 | 13 | 11 | 8 | 6 | 3 | 1 | 78
79 | 34 | 31 | 28 | 25 | 22 | 19 | 17 | 14 | 12 | 9 | 7 | 4 | 2 | 79
| | | | | | | | | | | | | |
80 | 35 | 32 | 29 | 26 | 23 | 20 | 18 | 15 | 13 | 10 | 8 | 6 | 3 | 80
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------
_t._ |18°.0|19°.0|20°.0|21°.0|22°.0|23°.0|24°.0|25°.0|26°.0|27°.0|28°.0|29°.0|30°.0| _t._
======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======
TABLE II.——RELATIVE HUMIDITY, PER CENT.
======+=======================================================================+======
_t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_
(Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry
ther.)| 1°.0| 2°.0| 3°.0| 4°.0| 5°.0| 6°.0| 7°.0| 8°.0| 9°.0|10°.0|11°.0|12°.0|ther.)
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-------
80 | 96 | 92 | 87 | 83 | 79 | 75 | 72 | 68 | 64 | 61 | 57 | 54 | 80
81 | 96 | 92 | 88 | 84 | 80 | 76 | 72 | 68 | 65 | 61 | 58 | 54 | 81
82 | 96 | 92 | 88 | 84 | 80 | 76 | 72 | 69 | 65 | 62 | 58 | 55 | 82
83 | 96 | 92 | 88 | 84 | 80 | 76 | 73 | 69 | 66 | 62 | 59 | 55 | 83
84 | 96 | 92 | 88 | 84 | 80 | 77 | 73 | 69 | 66 | 63 | 59 | 56 | 84
| | | | | | | | | | | | |
85 | 96 | 92 | 88 | 84 | 80 | 77 | 73 | 70 | 66 | 63 | 60 | 56 | 85
86 | 96 | 92 | 88 | 84 | 81 | 77 | 73 | 70 | 67 | 63 | 60 | 57 | 86
87 | 96 | 92 | 88 | 84 | 81 | 77 | 74 | 70 | 67 | 64 | 60 | 57 | 87
88 | 96 | 92 | 88 | 85 | 81 | 77 | 74 | 71 | 67 | 64 | 61 | 58 | 88
89 | 96 | 92 | 88 | 85 | 81 | 78 | 74 | 71 | 68 | 64 | 61 | 58 | 89
| | | | | | | | | | | | |
90 | 96 | 92 | 88 | 85 | 81 | 78 | 75 | 71 | 68 | 65 | 62 | 59 | 90
91 | 96 | 92 | 89 | 85 | 82 | 78 | 75 | 71 | 68 | 65 | 62 | 59 | 91
92 | 96 | 92 | 89 | 85 | 82 | 78 | 75 | 72 | 69 | 65 | 62 | 59 | 92
93 | 96 | 93 | 89 | 85 | 82 | 78 | 75 | 72 | 69 | 66 | 63 | 60 | 93
94 | 96 | 93 | 89 | 86 | 82 | 79 | 75 | 72 | 69 | 66 | 63 | 60 | 94
| | | | | | | | | | | | |
95 | 96 | 93 | 89 | 86 | 82 | 79 | 76 | 72 | 69 | 66 | 63 | 60 | 95
96 | 96 | 93 | 89 | 86 | 82 | 79 | 76 | 73 | 70 | 67 | 64 | 61 | 96
97 | 96 | 93 | 89 | 86 | 82 | 79 | 76 | 73 | 70 | 67 | 64 | 61 | 97
98 | 96 | 93 | 89 | 86 | 83 | 79 | 76 | 73 | 70 | 67 | 64 | 61 | 98
99 | 96 | 93 | 89 | 86 | 83 | 80 | 76 | 73 | 70 | 68 | 65 | 62 | 99
| | | | | | | | | | | | |
100 | 97 | 93 | 90 | 86 | 83 | 80 | 77 | 74 | 71 | 68 | 65 | 62 | 100
101 | 97 | 93 | 90 | 86 | 83 | 80 | 77 | 74 | 71 | 68 | 65 | 62 | 101
102 | 97 | 93 | 90 | 86 | 83 | 80 | 77 | 74 | 71 | 68 | 65 | 63 | 102
103 | 97 | 93 | 90 | 87 | 83 | 80 | 77 | 74 | 71 | 69 | 66 | 63 | 103
104 | 97 | 93 | 90 | 87 | 83 | 80 | 77 | 74 | 72 | 69 | 66 | 63 | 104
| | | | | | | | | | | | |
105 | 97 | 93 | 90 | 87 | 84 | 81 | 78 | 75 | 72 | 69 | 66 | 64 | 105
106 | 97 | 93 | 90 | 87 | 84 | 81 | 78 | 75 | 72 | 69 | 66 | 64 | 106
107 | 97 | 93 | 90 | 87 | 84 | 81 | 78 | 75 | 72 | 69 | 67 | 64 | 107
108 | 97 | 93 | 90 | 87 | 84 | 81 | 78 | 75 | 72 | 70 | 67 | 64 | 108
109 | 97 | 93 | 90 | 87 | 84 | 81 | 78 | 75 | 73 | 70 | 67 | 65 | 109
| | | | | | | | | | | | |
110 | 97 | 94 | 90 | 87 | 84 | 81 | 78 | 76 | 73 | 70 | 67 | 65 | 110
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------
_t._ | 1°.0| 2°.0| 3°.0| 4°.0| 5°.0| 6°.0| 7°.0| 8°.0| 9°.0|10°.0|11°.0|12°.0| _t._
======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======
TABLE II.——RELATIVE HUMIDITY, PER CENT.
======+=============================================================================+======
_t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_
(Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry
ther.)|12°.0|13°.0|14°.0|15°.0|16°.0|17°.0|18°.0|19°.0|20°.0|21°.0|22°.0|23°.0|24°.0|ther.)
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------
80 | 54 | 51 | 47 | 44 | 41 | 38 | 35 | 32 | 29 | 26 | 23 | 20 | 18 | 80
81 | 54 | 51 | 48 | 44 | 41 | 38 | 35 | 33 | 30 | 27 | 24 | 21 | 19 | 81
82 | 55 | 52 | 48 | 45 | 42 | 39 | 36 | 33 | 31 | 28 | 25 | 22 | 20 | 82
83 | 55 | 52 | 49 | 46 | 43 | 40 | 37 | 34 | 31 | 29 | 26 | 23 | 21 | 83
84 | 56 | 53 | 49 | 46 | 44 | 41 | 38 | 35 | 32 | 29 | 27 | 24 | 22 | 84
| | | | | | | | | | | | | |
85 | 56 | 53 | 50 | 47 | 44 | 41 | 38 | 36 | 33 | 30 | 28 | 25 | 22 | 85
86 | 57 | 54 | 51 | 48 | 45 | 42 | 39 | 36 | 34 | 31 | 29 | 26 | 23 | 86
87 | 57 | 54 | 51 | 48 | 45 | 42 | 40 | 37 | 34 | 32 | 30 | 27 | 24 | 87
88 | 58 | 55 | 52 | 49 | 46 | 43 | 40 | 38 | 35 | 32 | 30 | 27 | 25 | 88
89 | 58 | 55 | 52 | 49 | 46 | 44 | 41 | 38 | 36 | 33 | 31 | 28 | 26 | 89
| | | | | | | | | | | | | |
90 | 59 | 56 | 53 | 50 | 47 | 44 | 41 | 39 | 36 | 34 | 32 | 29 | 26 | 90
91 | 59 | 56 | 53 | 50 | 47 | 45 | 42 | 39 | 37 | 35 | 33 | 30 | 27 | 91
92 | 59 | 56 | 54 | 51 | 48 | 45 | 43 | 40 | 37 | 35 | 33 | 30 | 28 | 92
93 | 60 | 57 | 54 | 51 | 48 | 46 | 43 | 41 | 38 | 36 | 34 | 31 | 29 | 93
94 | 60 | 57 | 54 | 52 | 49 | 46 | 44 | 41 | 39 | 36 | 34 | 31 | 29 | 94
| | | | | | | | | | | | | |
95 | 60 | 58 | 55 | 52 | 49 | 47 | 44 | 42 | 39 | 37 | 35 | 32 | 30 | 95
96 | 61 | 58 | 55 | 53 | 50 | 47 | 45 | 42 | 40 | 37 | 36 | 33 | 30 | 96
97 | 61 | 58 | 56 | 53 | 50 | 48 | 45 | 43 | 40 | 38 | 36 | 33 | 31 | 97
98 | 61 | 59 | 56 | 53 | 51 | 48 | 46 | 43 | 41 | 38 | 37 | 34 | 32 | 98
99 | 62 | 59 | 56 | 54 | 51 | 49 | 46 | 44 | 41 | 39 | 37 | 34 | 32 | 99
| | | | | | | | | | | | | |
100 | 62 | 59 | 57 | 54 | 51 | 49 | 47 | 44 | 42 | 39 | 37 | 35 | 33 | 100
101 | 62 | 60 | 57 | 54 | 52 | 49 | 47 | 45 | 42 | 40 | 38 | 36 | 33 | 101
102 | 63 | 60 | 57 | 55 | 52 | 50 | 47 | 45 | 43 | 40 | 38 | 36 | 34 | 102
103 | 63 | 60 | 58 | 55 | 53 | 50 | 48 | 45 | 43 | 41 | 39 | 37 | 34 | 103
104 | 63 | 61 | 58 | 55 | 53 | 51 | 48 | 46 | 44 | 41 | 39 | 37 | 35 | 104
| | | | | | | | | | | | | |
105 | 64 | 61 | 58 | 56 | 53 | 51 | 49 | 46 | 44 | 42 | 40 | 38 | 35 | 105
106 | 64 | 61 | 59 | 56 | 54 | 51 | 49 | 47 | 44 | 42 | 40 | 38 | 36 | 106
107 | 64 | 62 | 59 | 57 | 54 | 52 | 49 | 47 | 45 | 43 | 41 | 38 | 36 | 107
108 | 64 | 62 | 59 | 57 | 54 | 52 | 50 | 47 | 45 | 43 | 41 | 39 | 37 | 108
109 | 65 | 62 | 60 | 57 | 55 | 52 | 50 | 48 | 46 | 44 | 41 | 39 | 37 | 109
| | | | | | | | | | | | | |
110 | 65 | 62 | 60 | 57 | 55 | 53 | 50 | 48 | 46 | 44 | 42 | 40 | 38 | 110
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------
_t._ |12°.0|13°.0|14°.0|15°.0|16°.0|17°.0|18°.0|19°.0|20°.0|21°.0|22°.0|23°.0|24°.0| _t._
======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======
TABLE II.——RELATIVE HUMIDITY, PER CENT.
======+=============================================================================+======
_t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_
(Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry
ther.)|24°.0|25°.0|26°.0|27°.0|28°.0|29°.0|30°.0|31°.0|32°.0|33°.0|34°.0|35°.0|36°.0|ther.)
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------
80 | 18 | 15 | 13 | 10 | 8 | 6 | 3 | 1 | | | | | | 80
81 | 19 | 16 | 14 | 11 | 9 | 7 | 4 | 2 | | | | | | 81
82 | 20 | 17 | 15 | 12 | 10 | 8 | 5 | 3 | 1 | | | | | 82
83 | 21 | 18 | 16 | 13 | 11 | 9 | 6 | 4 | 2 | | | | | 83
84 | 22 | 19 | 17 | 14 | 12 | 10 | 8 | 5 | 3 | 1 | | | | 84
| | | | | | | | | | | | | |
85 | 22 | 20 | 17 | 15 | 13 | 11 | 9 | 6 | 4 | 2 | | | | 85
86 | 23 | 21 | 18 | 16 | 14 | 12 | 10 | 7 | 5 | 3 | 1 | | | 86
87 | 24 | 22 | 19 | 17 | 15 | 13 | 11 | 8 | 6 | 4 | 2 | | | 87
88 | 25 | 22 | 20 | 18 | 16 | 14 | 12 | 9 | 7 | 5 | 3 | 1 | | 88
89 | 26 | 23 | 21 | 19 | 16 | 14 | 12 | 10 | 8 | 6 | 4 | 2 | 1 | 89
| | | | | | | | | | | | | |
90 | 26 | 24 | 22 | 20 | 17 | 15 | 13 | 11 | 9 | 7 | 5 | 3 | 2 | 90
91 | 27 | 25 | 23 | 20 | 18 | 16 | 14 | 12 | 10 | 8 | 6 | 4 | 3 | 91
92 | 28 | 26 | 23 | 21 | 19 | 17 | 15 | 13 | 11 | 9 | 7 | 5 | 3 | 92
93 | 29 | 26 | 24 | 22 | 20 | 18 | 16 | 14 | 12 | 10 | 8 | 6 | 4 | 93
94 | 29 | 27 | 25 | 23 | 21 | 18 | 16 | 14 | 13 | 11 | 9 | 7 | 5 | 94
| | | | | | | | | | | | | |
95 | 30 | 28 | 25 | 23 | 21 | 19 | 17 | 15 | 13 | 11 | 10 | 8 | 6 | 95
96 | 30 | 28 | 26 | 24 | 22 | 20 | 18 | 16 | 14 | 12 | 10 | 9 | 7 | 96
97 | 31 | 29 | 27 | 25 | 23 | 21 | 19 | 17 | 15 | 13 | 11 | 10 | 8 | 97
98 | 32 | 29 | 27 | 25 | 23 | 21 | 19 | 18 | 16 | 14 | 12 | 10 | 9 | 98
99 | 32 | 30 | 28 | 26 | 24 | 22 | 20 | 18 | 16 | 15 | 13 | 11 | 10 | 99
| | | | | | | | | | | | | |
100 | 33 | 31 | 29 | 27 | 25 | 23 | 21 | 19 | 17 | 15 | 14 | 12 | 10 | 100
101 | 33 | 31 | 29 | 27 | 25 | 23 | 21 | 20 | 18 | 16 | 14 | 13 | 11 | 101
102 | 34 | 32 | 30 | 28 | 26 | 24 | 22 | 20 | 19 | 17 | 15 | 13 | 12 | 102
103 | 34 | 32 | 30 | 28 | 26 | 25 | 23 | 21 | 19 | 17 | 16 | 14 | 12 | 103
104 | 35 | 33 | 31 | 29 | 27 | 25 | 23 | 22 | 20 | 18 | 16 | 15 | 13 | 104
| | | | | | | | | | | | | |
105 | 35 | 33 | 31 | 30 | 28 | 26 | 24 | 22 | 20 | 19 | 17 | 15 | 14 | 105
106 | 36 | 34 | 32 | 30 | 28 | 26 | 25 | 23 | 21 | 19 | 18 | 16 | 14 | 106
107 | 36 | 34 | 32 | 31 | 29 | 27 | 25 | 23 | 22 | 20 | 18 | 17 | 15 | 107
108 | 37 | 35 | 33 | 31 | 29 | 27 | 26 | 24 | 22 | 21 | 19 | 17 | 16 | 108
109 | 37 | 35 | 33 | 32 | 30 | 28 | 26 | 25 | 23 | 21 | 20 | 18 | 16 | 109
| | | | | | | | | | | | | |
110 | 38 | 36 | 34 | 32 | 30 | 28 | 27 | 25 | 23 | 22 | 20 | 19 | 17 | 110
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------
_t._ |24°.0|25°.0|26°.0|27°.0|28°.0|29°.0|30°.0|31°.0|32°.0|33°.0|34°.0|35°.0|36°.0| _t._
======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======
TABLE II.——RELATIVE HUMIDITY, PER CENT.
======+=======================================================================+======
_t_ | Difference between the dry and wet thermometers (_t-t′_). | _t_
(Dry +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+(Dry
ther.)|36°.0|37°.0|38°.0|39°.0|40°.0|41°.0|42°.0|43°.0|44°.0|45°.0|46°.0|48°.0|Ther.)
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------
89 | 1 | | | | | | | | | | | | 89
| | | | | | | | | | | | |
90 | 2 | | | | | | | | | | | | 90
91 | 3 | 1 | | | | | | | | | | | 91
92 | 3 | 2 | 1 | | | | | | | | | | 92
93 | 4 | 3 | 2 | | | | | | | | | | 93
94 | 5 | 4 | 3 | 0 | | | | | | | | | 94
| | | | | | | | | | | | |
95 | 6 | 5 | 4 | 1 | | | | | | | | | 95
96 | 7 | 5 | 5 | 2 | 1 | | | | | | | | 96
97 | 8 | 6 | 6 | 3 | 1 | | | | | | | | 97
98 | 9 | 7 | 7 | 4 | 2 | 1 | | | | | | | 98
99 | 10 | 8 | 7 | 5 | 3 | 2 | 0 | | | | | | 99
| | | | | | | | | | | | |
100 | 10 | 9 | 8 | 6 | 4 | 3 | 1 | | | | | | 100
101 | 11 | 9 | 9 | 6 | 5 | 3 | 2 | 0 | | | | | 101
102 | 12 | 10 | 9 | 7 | 6 | 4 | 3 | 1 | | | | | 102
103 | 12 | 11 | 9 | 8 | 6 | 5 | 4 | 2 | 1 | | | | 103
104 | 13 | 12 | 10 | 8 | 7 | 6 | 5 | 3 | 2 | | | | 104
| | | | | | | | | | | | |
105 | 14 | 12 | 11 | 9 | 8 | 6 | 5 | 4 | 2 | 1 | | | 105
106 | 14 | 13 | 11 | 10 | 8 | 7 | 6 | 4 | 3 | 2 | 0 | | 106
107 | 15 | 14 | 12 | 11 | 9 | 8 | 6 | 5 | 4 | 3 | 1 | | 107
108 | 16 | 14 | 13 | 11 | 10 | 9 | 7 | 6 | 5 | 3 | 2 | | 108
109 | 16 | 15 | 13 | 12 | 10 | 9 | 8 | 7 | 5 | 4 | 3 | | 109
| | | | | | | | | | | | |
110 | 17 | 15 | 14 | 13 | 11 | 10 | 8 | 7 | 6 | 5 | 3 | 1 | 110
------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+------
_t._ |36°.0|37°.0|38°.0|39°.0|40°.0|41°.0|42°.0|43°.0|44°.0|45°.0|46°.0|48°.0| _t._
======+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+======
TABLE III.——REDUCTION OF BAROMETER READING TO 32°.
===+=========================================================================================
| Inches.
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
°F | 24.0| 24.5| 25.0| 25.5| 26.0| 26.5| 27.0| 27.5| 28.0| 28.5| 29.0| 29.5| 30.0| 30.5| 31.0
---+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
30|-.003|-.003|-.003|-.003|-.003|-.003|-.003|-.003|-.003|-.004|-.004|-.004|-.004|-.004|-.004
31| .005| .005| .005| .005| .006| .006| .006| .006| .006| .006| .006| .006| .006| .007| .007
32| .007| .008| .008| .008| .008| .008| .008| .008| .009| .009| .009| .009| .009| .009| .009
33| .010| .010| .010| .010| .010| .010| .011| .011| .011| .011| .012| .012| .012| .012| .012
34| .012| .012| .012| .012| .013| .013| .013| .013| .014| .014| .014| .014| .015| .015| .015
| | | | | | | | | | | | | | |
35| .014| .014| .014| .015| .015| .015| .016| .016| .016| .016| .017| .017| .017| .018| .018
36| .016| .016| .017| .017| .017| .018| .018| .018| .019| .019| .019| .020| .020| .020| .021
37| .018| .019| .019| .019| .020| .020| .021| .021| .021| .022| .022| .022| .023| .023| .024
38| .020| .021| .021| .022| .022| .022| .023| .023| .024| .024| .025| .025| .026| .026| .026
39| .023| .023| .024| .024| .024| .025| .025| .026| .026| .027| .027| .028| .028| .029| .029
| | | | | | | | | | | | | | |
40| .025| .025| .026| .026| .027| .027| .028| .028| .029| .030| .030| .030| .031| .031| .032
41| .027| .027| .028| .029| .029| .030| .030| .031| .031| .032| .033| .033| .034| .034| .035
42| .029| .030| .030| .031| .032| .032| .033| .033| .034| .034| .035| .036| .036| .037| .038
43| .031| .032| .033| .033| .034| .035| .035| .036| .036| .037| .038| .038| .039| .040| .040
44| .033| .034| .035| .035| .036| .037| .038| .038| .039| .040| .040| .041| .042| .042| .043
| | | | | | | | | | | | | | |
45| .036| .037| .037| .038| .039| .039| .040| .041| .042| .042| .043| .044| .045| .045| .046
46| .038| .038| .039| .040| .041| .042| .043| .043| .044| .045| .046| .046| .047| .048| .049
47| .040| .041| .042| .042| .043| .044| .045| .046| .047| .048| .048| .049| .050| .051| .052
48| .042| .043| .044| .045| .046| .047| .047| .048| .049| .050| .051| .052| .053| .053| .054
49| .044| .045| .046| .047| .048| .049| .050| .051| .052| .052| .054| .054| .055| .056| .057
| | | | | | | | | | | | | | |
50| .046| .047| .048| .049| .050| .051| .052| .053| .054| .055| .056| .057| .058| .059| .060
51| .049| .050| .051| .052| .053| .054| .055| .056| .057| .058| .059| .060| .061| .062| .063
52| .051| .052| .053| .054| .055| .056| .057| .058| .059| .060| .061| .062| .064| .065| .066
53| .053| .054| .055| .056| .057| .058| .060| .061| .062| .063| .064| .065| .066| .067| .068
54| .055| .056| .057| .058| .060| .061| .062| .063| .064| .065| .067| .068| .069| .070| .071
| | | | | | | | | | | | | | |
55| .057| .058| .060| .061| .062| .063| .064| .065| .066| .068| .069| .070| .071| .073| .074
56| .060| .061| .062| .063| .064| .065| .067| .068| .069| .070| .072| .073| .074| .075| .077
57| .062| .063| .064| .065| .067| .068| .069| .070| .072| .073| .075| .076| .077| .078| .080
58| .064| .065| .066| .068| .069| .070| .071| .073| .074| .076| .077| .078| .080| .081| .082
59| .066| .068| .069| .070| .072| .073| .074| .075| .077| .078| .080| .081| .083| .084| .085
| | | | | | | | | | | | | | |
60| .068| .070| .071| .072| .074| .076| .077| .078| .079| .081| .082| .084| .085| .086| .088
61| .070| .072| .073| .074| .076| .077| .079| .080| .082| .083| .085| .086| .088| .089| .091
62| .073| .074| .076| .077| .079| .080| .082| .083| .085| .086| .088| .089| .091| .092| .094
63| .075| .076| .078| .079| .081| .082| .084| .085| .087| .088| .090| .091| .093| .095| .096
64| .077| .078| .080| .081| .083| .085| .086| .088| .090| .091| .093| .094| .096| .097| .099
| | | | | | | | | | | | | | |
65|-.079|-.080|-.082|-.084|-.086|-.087|-.089|-.090|-.092|-.093|-.095|-.097|-.099|-.100|-.102
===+=========================================================================================
TABLE III.——REDUCTION OF BAROMETER READING TO 32°.——_Continued._
===+=========================================================================================
| Inches.
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
°F | 24.0| 24.5| 25.0| 25.5| 26.0| 26.5| 27.0| 27.5| 28.0| 28.5| 29.0| 29.5| 30.0| 30.5| 31.0
---+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
65|-.079|-.080|-.082|-.084|-.086|-.087|-.089|-.090|-.092|-.093|-.095|-.097|-.099|-.100|-.102
66| .081| .083| .085| .086| .088| .089| .091| .093| .095| .096| .098| .099| .101| .103| .105
67| .083| .085| .087| .088| .090| .092| .094| .095| .097| .099| .101| .102| .104| .106| .108
68| .085| .087| .089| .090| .093| .094| .096| .098| .100| .101| .103| .105| .107| .108| .110
69| .088| .089| .091| .093| .095| .097| .099| .100| .102| .104| .106| .107| .110| .111| .113
| | | | | | | | | | | | | | |
70| .090| .092| .094| .096| .097| .099| .101| .103| .105| .106| .109| .110| .112| .114| .116
71| .092| .094| .096| .098| .100| .101| .103| .105| .107| .109| .111| .113| .115| .116| .119
72| .094| .096| .098| .100| .102| .104| .106| .108| .110| .112| .114| .116| .118| .120| .122
73| .096| .098| .100| .102| .104| .106| .108| .110| .112| .114| .116| .118| .120| .122| .124
74| .098| .100| .103| .105| .107| .109| .111| .113| .115| .117| .119| .121| .123| .125| .127
| | | | | | | | | | | | | | |
75| .101| .102| .105| .106| .109| .111| .113| .115| .117| .119| .122| .124| .126| .128| .130
76| .103| .104| .107| .109| .111| .113| .116| .118| .120| .122| .124| .126| .128| .130| .133
77| .105| .107| .109| .111| .114| .116| .118| .120| .122| .124| .127| .129| .131| .133| .136
78| .107| .109| .112| .113| .116| .118| .120| .122| .125| .127| .129| .131| .134| .136| .138
79| .109| .111| .114| .116| .118| .120| .123| .125| .127| .129| .132| .134| .137| .139| .141
| | | | | | | | | | | | | | |
80| .111| .113| .116| .118| .121| .123| .125| .127| .130| .132| .135| .137| .139| .141| .144
81| .114| .116| .118| .120| .123| .125| .128| .130| .132| .134| .137| .139| .142| .144| .147
82| .116| .118| .121| .122| .125| .128| .130| .132| .135| .137| .140| .142| .145| .147| .149
83| .118| .120| .123| .125| .128| .130| .133| .135| .138| .140| .142| .145| .147| .149| .152
84| .120| .122| .125| .127| .130| .132| .135| .138| .140| .142| .145| .147| .150| .152| .155
| | | | | | | | | | | | | | |
85| .122| .124| .127| .129| .132| .134| .137| .139| .143| .145| .148| .150| .153| .155| .158
86| .124| .126| .128| .130| .135| .137| .140| .143| .145| .148| .150| .153| .155| .158| .161
87| .126| .129| .132| .134| .137| .139| .142| .144| .148| .150| .153| .155| .158| .161| .163
88| .129| .131| .134| .137| .139| .142| .145| .147| .150| .152| .155| .158| .161| .163| .166
89| .131| .133| .136| .139| .142| .144| .147| .150| .153| .155| .158| .161| .164| .166| .169
| | | | | | | | | | | | | | |
90| .133| .136| .138| .141| .144| .147| .150| .153| .155| .157| .161| .164| .166| .169| .172
91| .135| .138| .141| .143| .146| .149| .152| .155| .158| .160| .163| .166| .169| .172| .175
92| .137| .140| .143| .146| .149| .152| .154| .157| .160| .163| .166| .169| .172| .175| .177
93| .139| .142| .145| .148| .151| .154| .157| .160| .163| .166| .168| .171| .174| .177| .180
94| .142| .145| .147| .150| .153| .156| .159| .162| .165| .168| .171| .174| .177| .180| .183
| | | | | | | | | | | | | | |
95| .144| .147| .150| .153| .156| .159| .162| .165| .168| .171| .174| .177| .180| .183| .186
96| .146| .149| .152| .155| .158| .161| .164| .167| .170| .173| .176| .179| .182| .185| .188
97| .148| .151| .154| .157| .160| .164| .167| .170| .173| .176| .179| .182| .185| .188| .191
98| .150| .153| .156| .160| .163| .166| .169| .172| .175| .178| .181| .185| .188| .191| .194
99| .152| .155| .159| .162| .165| .168| .171| .175| .178| .181| .184| .187| .190| .194| .197
| | | | | | | | | | | | | | |
100|-.154|-.157|-.161|-.164|-.167|-.171|-.174|-.177|-.180|-.184|-.187|-.190|-.193|-.197|-.200
---+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
TABLE IV.——TABLE FOR REDUCING OBSERVATIONS OF THE BAROMETER TO
SEA LEVEL, CORRECTION ADDITIVE.
==========+=======================================================================
Height, in| Temperature of external air——degrees Fahrenheit.
feet. |
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
| -20°| -10°| 0° | 10°| 20°| 30°| 40°| 50°| 60°| 70°| 80°| 90°| 100°
----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
10| .013| .013| .012| .012| .012| .012| .011| .011| .011| .011| .010| .010| .010
20| .026| .025| .025| .024| .023| .023| .023| .022| .022| .021| .021| .020| .020
30| .039| .038| .037| .036| .035| .034| .034| .033| .032| .032| .031| .030| .030
40| .052| .050| .049| .048| .047| .046| .045| .044| .043| .042| .041| .040| .040
| | | | | | | | | | | | |
50| .065| .063| .061| .060| .059| .058| .056| .055| .054| .053| .052| .051| .050
60| .077| .076| .074| .072| .070| .069| .068| .066| .065| .063| .062| .061| .059
70| .090| .088| .086| .084| .082| .081| .078| .077| .076| .074| .072| .071| .069
80| .103| .101| .098| .096| .094| .092| .090| .088| .086| .084| .082| .081| .079
90| .116| .113| .111| .108| .105| .104| .101| .099| .097| .095| .093| .091| .089
| | | | | | | | | | | | |
100| .129| .126| .123| .120| .117| .115| .112| .110| .108| .105| .103| .101| .099
110| .142| .139| .135| .132| .129| .126| .123| .121| .119| .116| .113| .111| .109
120| .155| .151| .148| .144| .140| .138| .134| .132| .129| .126| .124| .121| .119
130| .168| .164| .160| .156| .152| .149| .146| .143| .140| .137| .134| .131| .129
140| .181| .176| .172| .168| .164| .161| .157| .154| .151| .147| .144| .141| .139
| | | | | | | | | | | | |
150| .194| .189| .185| .180| .176| .172| .168| .165| .162| .158| .155| .152| .149
160| .206| .201| .197| .192| .187| .183| .179| .176| .172| .168| .165| .162| .158
170| .219| .214| .209| .204| .199| .195| .190| .187| .183| .179| .175| .172| .168
180| .232| .227| .222| .216| .211| .206| .202| .198| .194| .189| .185| .182| .178
190| .245| .239| .234| .228| .222| .218| .213| .209| .204| .200| .196| .192| .188
| | | | | | | | | | | | |
200| .258| .252| .246| .240| .234| .229| .224| .220| .215| .210| .206| .202| .198
210| .271| .264| .258| .252| .246| .240| .235| .231| .226| .221| .216| .212| .208
220| .284| .277| .270| .264| .257| .252| .246| .242| .236| .231| .227| .222| .218
230| .296| .289| .283| .276| .269| .263| .257| .253| .247| .242| .237| .232| .228
240| .309| .302| .295| .288| .281| .275| .269| .264| .258| .252| .248| .242| .238
| | | | | | | | | | | | |
250| .322| .314| .307| .300| .293| .286| .280| .275| .269| .263| .258| .253| .248
260| .335| .327| .319| .311| .304| .297| .291| .285| .279| .273| .268| .263| .257
270| .348| .339| .331| .323| .316| .309| .302| .296| .290| .284| .278| .273| .267
280| .360| .352| .344| .335| .328| .320| .314| .307| .301| .294| .288| .283| .277
290| .373| .364| .356| .347| .339| .332| .325| .318| .311| .305| .299| .293| .287
| | | | | | | | | | | | |
300| .386| .377| .368| .359| .351| .343| .336| .329| .322| .315| .309| .303| .297
310| .399| .389| .380| .371| .363| .354| .347| .340| .333| .326| .319| .313| .307
320| .412| .402| .392| .383| .374| .366| .358| .351| .343| .336| .329| .323| .317
330| .424| .414| .404| .395| .386| .377| .369| .362| .354| .347| .340| .333| .326
340| .437| .427| .416| .407| .397| .389| .380| .373| .365| .357| .350| .343| .336
| | | | | | | | | | | | |
350| .450| .439| .429| .419| .409| .400| .392| .384| .376| .368| .360| .353| .346
360| .463| .451| .441| .430| .421| .411| .403| .394| .386| .378| .370| .363| .356
370| .476| .464| .453| .442| .432| .423| .414| .405| .397| .389| .380| .373| .366
380| .488| .476| .465| .454| .444| .434| .425| .416| .408| .399| .391| .383| .375
390| .501| .489| .477| .466| .455| .446| .436| .427| .418| .410| .401| .393| .385
| | | | | | | | | | | | |
400| .514| .501| .489| .478| .467| .457| .447| .438| .429| .420| .411| .403| .395
410| .527| .513| .501| .490| .479| .468| .458| .449| .440| .430| .421| .413| .405
420| .539| .526| .513| .502| .490| .480| .469| .460| .450| .441| .431| .423| .415
430| .552| .538| .525| .513| .502| .491| .480| .470| .461| .451| .442| .433| .425
440| .565| .551| .537| .525| .513| .502| .491| .481| .471| .462| .452| .443| .434
| | | | | | | | | | | | |
450| .578| .563| .550| .537| .525| .513| .503| .492| .482| .472| .462| .453| .444
460| .590| .575| .562| .549| .537| .525| .514| .503| .493| .482| .472| .463| .454
470| .603| .588| .574| .561| .548| .536| .525| .514| .503| .493| .482| .473| .464
480| .616| .600| .586| .572| .560| .547| .536| .524| .514| .503| .493| .483| .474
490| .628| .613| .598| .584| .571| .559| .547| .535| .524| .514| .503| .493| .483
| | | | | | | | | | | | |
500| .641| .625| .610| .596| .583| .570| .558| .546| .535| .524| .513| .503| .493
510| .654| .637| .622| .608| .594| .581| .569| .557| .545| .534| .523| .513| .503
520| .666| .650| .634| .620| .606| .593| .580| .568| .556| .545| .533| .523| .513
530| .679| .662| .646| .631| .617| .604| .591| .578| .566| .555| .544| .533| .522
540| .691| .675| .658| .643| .629| .615| .602| .589| .577| .565| .554| .543| .532
====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====
TABLE IV.——FOR REDUCING OBSERVATIONS OF THE BAROMETER TO SEA
LEVEL.——_Continued._
==========+=======================================================================
Height, in| Temperature of external air——degrees Fahrenheit.
feet. |
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
| -20°| -10°| 0° | 10°| 20°| 30°| 40°| 50°| 60°| 70°| 80°| 90°| 100°
----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
550| .704| .687| .670| .655| .640| .626| .613| .600| .587| .575| .564| .553| .542
560| .717| .699| .683| .667| .652| .638| .624| .611| .598| .586| .574| .563| .552
570| .729| .712| .695| .679| .663| .649| .635| .622| .608| .596| .584| .573| .562
580| .742| .724| .707| .690| .675| .660| .646| .632| .619| .606| .595| .583| .571
590| .754| .737| .719| .702| .686| .672| .657| .643| .629| .617| .605| .593| .581
| | | | | | | | | | | | |
600| .767| .749| .731| .714| .698| .683| .668| .654| .640| .627| .615| .603| .591
610| .780| .761| .743| .726| .709| .694| .679| .665| .650| .637| .625| .613| .601
620| .792| .774| .755| .738| .721| .705| .690| .675| .661| .648| .635| .623| .611
630| .805| .786| .767| .749| .732| .717| .701| .686| .671| .658| .645| .633| .620
640| .817| .798| .779| .761| .744| .728| .712| .697| .682| .668| .655| .643| .630
| | | | | | | | | | | | |
650| .830| .811| .791| .773| .755| .739| .723| .708| .692| .679| .666| .653| .640
660| .843| .823| .803| .785| .767| .750| .734| .718| .703| .689| .676| .662| .650
670| .855| .835| .815| .797| .778| .761| .745| .729| .713| .699| .686| .672| .660
680| .868| .847| .827| .808| .790| .773| .756| .740| .724| .709| .696| .682| .669
690| .880| .860| .839| .820| .801| .784| .767| .750| .734| .720| .706| .692| .679
| | | | | | | | | | | | |
700| .893| .872| .851| .832| .813| .795| .778| .761| .745| .730| .716| .702| .689
710| .905| .884| .863| .844| .824| .806| .789| .772| .755| .740| .726| .712| .698
720| .918| .896| .875| .855| .836| .817| .800| .782| .766| .751| .736| .722| .708
730| .930| .909| .887| .867| .847| .829| .811| .793| .776| .761| .746| .732| .718
740| .943| .921| .899| .879| .859| .840| .822| .804| .787| .771| .756| .742| .728
| | | | | | | | | | | | |
750| .955| .933| .911| .891| .870| .851| .833| .815| .797| .782| .767| .752| .738
760| .968| .945| .922| .902| .881| .862| .843| .825| .808| .792| .777| .761| .747
770| .980| .957| .934| .914| .893| .873| .854| .836| .818| .802| .787| .771| .757
780| .993| .970| .946| .926| .904| .885| .865| .847| .829| .812| .797| .781| .767
790|1.005| .982| .958| .937| .916| .896| .876| .857| .839| .823| .807| .791| .776
| | | | | | | | | | | | |
800|1.018| .994| .970| .949| .927| .907| .887| .868| .850| .833| .817| .801| .786
810|1.030|1.006| .982| .961| .938| .918| .898| .878| .860| .843| .827| .811| .796
820|1.043|1.018| .994| .972| .950| .929| .909| .889| .871| .854| .937| .821| .805
830|1.055|1.031|1.006| .984| .961| .940| .920| .900| .881| .864| .847| .831| .815
840|1.068|1.043|1.018| .995| .973| .951| .931| .911| .892| .874| .857| .841| .825
| | | | | | | | | | | | |
850|1.080|1.055|1.030|1.007| .984| .962| .942| .922| .902| .885| .867| .851| .835
860|1.093|1.067|1.041|1.019| .995| .974| .952| .932| .913| .895| .877| .860| .844
870|1.105|1.079|1.053|1.030|1.007| .985| .963| .943| .923| .905| .887| .870| .854
880|1.118|1.092|1.065|1.042|1.018| .996| .974| .954| .934| .915| .897| .880| .864
890|1.130|1.104|1.077|1.053|1.030|1.007| .985| .904| .944| .926| .907| .890| .873
| | | | | | | | | | | | |
900|1.143|1.116|1.089|1.065|1.041|1.018| .996| .975| .955| .936| .917| .900| .883
910|1.155|1.128|1.101|1.077|1.052|1.029|1.007| .986| .965| .946| .927| .910| .893
920|1.168|1.140|1.113|1.088|1.064|1.040|1.018| .996| .976| .956| .937| .920| .902
930|1.180|1.152|1.125|1.100|1.075|1.051|1.029|1.007| .986| .967| .947| .929| .912
940|1.193|1.164|1.137|1.111|1.086|1.062|1.040|1.017| .997| .977| .957| .939| .921
| | | | | | | | | | | | |
950|1.205|1.177|1.149|1.123|1.098|1.074|1.051|1.028|1.007| .987| .967| .949| .931
960|1.217|1.189|1.160|1.135|1.109|1.085|1.061|1.039|1.017| .997| .977| .959| .941
970|1.230|1.201|1.172|1.146|1.120|1.096|1.072|1.049|1.028|1.007| .987| .969| .950
980|1.242|1.213|1.184|1.158|1.131|1.107|1.083|1.060|1.038|1.018| .997| .978| .960
990|1.255|1.225|1.196|1.169|1.143|1.118|1.094|1.070|1.049|1.028|1.007| .988| .969
| | | | | | | | | | | | |
1000|1.267|1.237|1.208|1.181|1.154|1.129|1.105|1.081|1.059|1.038|1.017| .998| .979
1010|1.279|1.249|1.220|1.192|1.165|1.140|1.116|1.092|1.069|1.048|1.027|1.008| .989
1020|1.292|1.261|1.232|1.204|1.177|1.151|1.127|1.102|1.080|1.058|1.037|1.018| .998
1030|1.304|1.273|1.243|1.215|1.188|1.162|1.137|1.113|1.090|1.069|1.047|1.027|1.008
1040|1.317|1.285|1.255|1.227|1.199|1.173|1.148|1.123|1.101|1.079|1.057|1.037|1.017
| | | | | | | | | | | | |
1050|1.329|1.298|1.267|1.238|1.211|1.184|1.159|1.134|1.111|1.089|1.067|1.047|1.027
1060|1.341|1.310|1.279|1.250|1.222|1.195|1.170|1.145|1.121|1.099|1.077|1.057|1.037
1070|1.354|1.322|1.291|1.261|1.233|1.206|1.181|1.155|1.132|1.109|1.087|1.067|1.046
1080|1.366|1.334|1.302|1.273|1.244|1.217|1.191|1.166|1.142|1.120|1.097|1.076|1.056
1090|1.379|1.346|1.314|1.284|1.256|1.228|1.202|1.176|1.153|1.130|1.107|1.086|1.065
====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====
TABLE IV.——FOR REDUCING OBSERVATIONS OF THE BAROMETER TO SEA
LEVEL.——_Continued._
==========+=======================================================================
Height, in| Temperature of external air——degrees Fahrenheit.
feet. |
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
| -20°| -10°| 0° | 10°| 20°| 30°| 40°| 50°| 60°| 70°| 80°| 90°| 100°
----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----
1100|1.391|1.358|1.326|1.296|1.267|1.239|1.213|1.187|1.163|1.140|1.117|1.096|1.075
1110|1.403|1.370|1.338|1.307|1.278|1.250|1.224|1.198|1.173|1.150|1.127|1.106|1.085
1120|1.416|1.382|1.350|1.319|1.289|1.261|1.235|1.208|1.184|1.160|1.137|1.115|1.094
1130|1.428|1.394|1.361|1.330|1.301|1.272|1.245|1.219|1.194|1.170|1.147|1.125|1.104
1140|1.440|1.406|1.373|1.342|1.312|1.283|1.256|1.229|1.204|1.180|1.157|1.135|1.113
| | | | | | | | | | | | |
1150|1.453|1.418|1.385|1.353|1.323|1.294|1.267|1.240|1.215|1.191|1.167|1.145|1.123
1160|1.465|1.430|1.397|1.365|1.334|1.305|1.278|1.251|1.225|1.201|1.177|1.154|1.133
1170|1.477|1.442|1.409|1.376|1.345|1.315|1.289|1.261|1.235|1.211|1.187|1.164|1.142
1180|1.489|1.454|1.420|1.388|1.357|1.327|1.299|1.272|1.245|1.221|1.197|1.174|1.152
1190|1.502|1.466|1.432|1.399|1.368|1.338|1.310|1.282|1.256|1.231|1.207|1.183|1.161
| | | | | | | | | | | | |
1200|1.514|1.478|1.444|1.411|1.379|1.349|1.321|1.293|1.266|1.241|1.217|1.193|1.171
1210|1.526|1.490|1.456|1.422|1.390|1.360|1.332|1.303|1.276|1.251|1.227|1.203|1.180
1220|1.539|1.502|1.467|1.434|1.401|1.371|1.342|1.314|1.288|1.261|1.237|1.212|1.190
1230|1.551|1.514|1.479|1.445|1.413|1.382|1.353|1.324|1.297|1.271|1.247|1.222|1.199
1240|1.563|1.526|1.491|1.457|1.424|1.393|1.364|1.335|1.307|1.281|1.257|1.232|1.209
| | | | | | | | | | | | |
1250|1.576|1.538|1.502|1.468|1.435|1.404|1.374|1.345|1.317|1.291|1.266|1.242|1.218
1260|1.588|1.550|1.514|1.479|1.446|1.415|1.385|1.356|1.328|1.302|1.276|1.251|1.228
1270|1.600|1.562|1.526|1.491|1.457|1.426|1.396|1.366|1.338|1.312|1.286|1.261|1.237
1280|1.612|1.574|1.538|1.502|1.469|1.437|1.407|1.377|1.348|1.322|1.296|1.271|1.247
1290|1.625|1.586|1.549|1.514|1.480|1.448|1.417|1.387|1.359|1.332|1.306|1.280|1.256
| | | | | | | | | | | | |
1300|1.637|1.598|1.561|1.525|1.491|1.459|1.428|1.398|1.369|1.342|1.316|1.290|1.266
1310|1.649|1.610|1.573|1.536|1.502|1.470|1.439|1.408|1.379|1.352|1.326|1.300|1.275
1320|1.661|1.622|1.584|1.548|1.513|1.481|1.449|1.419|1.390|1.362|1.336|1.309|1.285
1330|1.674|1.634|1.596|1.559|1.525|1.492|1.460|1.429|1.400|1.372|1.346|1.319|1.294
1340|1.686|1.640|1.608|1.571|1.536|1.503|1.471|1.440|1.410|1.382|1.356|1.329|1.304
| | | | | | | | | | | | |
1350|1.698|1.658|1.620|1.582|1.547|1.514|1.482|1.450|1.420|1.393|1.366|1.339|1.313
1360|1.710|1.669|1.631|1.593|1.558|1.524|1.492|1.461|1.431|1.403|1.375|1.348|1.323
1870|1.722|1.681|1.643|1.605|1.569|1.535|1.503|1.471|1.441|1.413|1.385|1.358|1.332
1380|1.735|1.693|1.655|1.616|1.581|1.546|1.514|1.482|1.451|1.423|1.395|1.368|1.342
1390|1.747|1.705|1.666|1.628|1.592|1.557|1.524|1.492|1.462|1.433|1.405|1.377|1.351
| | | | | | | | | | | | |
1400|1.759|1.717|1.678|1.639|1.603|1.568|1.535|1.503|1.472|1.443|1.415|1.387|1.361
1410|1.771|1.729|1.690|1.650|1.614|1.579|1.546|1.513|1.482|1.453|1.425|1.397|1.370
1420|1.783|1.741|1.701|1.662|1.625|1.590|1.556|1.524|1.492|1.463|1.435|1.406|1.380
1430|1.796|1.753|1.713|1.673|1.636|1.601|1.567|1.534|1.503|1.473|1.444|1.416|1.389
1440|1.808|1.765|1.724|1.685|1.047|1.612|1.577|1.545|1.513|1.483|1.454|1.426|1.399
| | | | | | | | | | | | |
1450|1.820|1.777|1.736|1.696|1.658|1.623|1.588|1.555|1.523|1.493|1.464|1.436|1.408
1460|1.832|1.788|1.748|1.707|1.670|1.633|1.599|1.565|1.533|1.503|1.474|1.445|1.418
1470|1.844|1.800|1.759|1.719|1.081|1.644|1.609|1.576|1.543|1.513|1.484|1.455|1.427
1480|1.857|1.812|1.771|1.730|1.692|1.655|1.620|1.586|1.554|1.523|1.493|1.465|1.437
1490|1.869|1.824|1.782|1.742|1.703|1.666|1.630|1.597|1.564|1.533|1.503|1.474|1.446
| | | | | | | | | | | | |
1500|1.881|1.836|1.794|1.753|1.714|1.677|1.641|1.607|1.574|1.543|1.513|1.484|1.456
====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====+=====
APPENDIX A.
SUGGESTIONS TO TEACHERS.
It is the object of this book to lead the student to the independent
discovery of the most important facts in our ordinary weather conditions,
and of the interrelations of the different weather elements. This
practical study having taught something as to the real nature of
atmospheric phenomena by actual observation, rapid and substantial
progress may be made in the knowledge of the distribution and of the
explanation of similar phenomena in other parts of the world, as derived
through a study of the text-books. By means of this combination of the two
kinds of study, the inductive and the didactic, the advantages of both may
be preserved, and the slow progress of the first method and the unsound
progress of the second may be avoided. This book is not a text-book, and
it therefore does not attempt to give explanations of various phenomena
discovered by the class. Explanations will, of course, be called for by
the scholars, in increasing number as the work progresses, and the larger
relations of the study become apparent. It is best, if possible, to leave
the more complicated matters (such as the cause of the deflection of the
wind from the gradient, of cyclones and anticyclones, etc.) until the
subjects can be taken up in detail and fully explained, for instance in
the later years of the high school course. It is not advisable to raise
such complicated questions in the grammar school work if they can be
avoided. The teacher who has a fairly good knowledge of one comprehensive
modern text-book of meteorology, such as Davis’s _Elementary Meteorology_,
will find himself sufficiently well equipped to answer the questions put
by the class.
The value of the work outlined in this little book can be much increased
if the larger applications of the lessons here learned are strongly
emphasized. Suggestions along this line have been made in fine print
throughout the text, but the examples given may be further extended to the
great advantage of the student. Careful attention ought to be given to the
formulating and writing out of the generalizations reached by the class,
for in these written summaries the results are preserved in compact form.
CHAPTER I.
The work outlined in this chapter is adapted to the lower grades in the
grammar school. It is assumed that the pupils have already had some
preliminary training in the simplest non-instrumental weather
observations, such as can readily be made during the primary school years.
For the convenience of teachers who may desire it, a brief outline of work
suited to the primary school grades is here given. It is desirable that
even older scholars be given some such training as this before they take
up the exercises of Chapter II.
The central idea in this elementary work is to train the children in
intelligent weather observation, so that they may come to appreciate what
our typical weather changes are; that they may recognize the types as they
recur, and may see how each example differs from, or accords with, those
that have preceded it. We are all so directly affected by the weather
conditions prevailing at any time that even the youngest children are
forced, unconsciously to be sure, to take some notice of these changes.
The work of the teacher is, therefore, simply to direct attention to what
is already seen.
When the children come to school on some snowy winter day, with a
northeast wind, chilling and damp, attention may be called to the need of
overshoes and overcoats, to the piling up of the snow in deep drifts at
certain places near the school or in the town, while in other places the
ground is left bare; to the ease with which snowballs may be made, and to
other facts which will very readily suggest themselves. A day or two after
such a storm, when the sun is shining bright in a cloudless sky, when
there is no wind and the air is dry, cold, and crisp, the contrasts
between these two weather types should be brought out. Instead of snow we
now have sunshine: instead of a damp, chilling northeaster we now have a
calm and the air is dry; snowballs cannot easily be made in the early
morning because the snow is frozen hard and is too dry, but towards noon,
if the temperature rise high enough, there may be thawing on the tops or
sides of the snowdrifts, and there the snow becomes soft enough for
snowballing. Another weather type, often noted during our winter in the
central and eastern United States, and strongly contrasted with both of
the preceding conditions, is that which brings us a warm, damp, southerly
wind, frequently accompanied by heavy rains. As these damp winds blow over
snow-covered surfaces they become foggy and the ground is said to “smoke”;
the heavy rain rapidly melts the snow; slush and mud make bad walking;
rivers and brooks rise rapidly, perhaps overflowing their banks; low-lying
places become filled with standing water. These and other features should
all be brought out by the teacher, not by telling the class of them
directly, but by judicious questioning, and they should be contrasted with
the conditions which may immediately follow, when the storm has cleared
off, and when the low temperatures brought by a cold wave, with its dry
northwest wind, have resulted in freezing lakes, rivers, and brooks, and
when skating and sliding may be indulged in. Early summer weather
conditions, with their characteristic warm spells, cumulus clouds,
thunderstorms, and (near the coast) sea breezes, furnish another long list
of typical changes that should be just as carefully noted and described as
the more striking winter characteristics. Autumn types add further to the
list, which might be extended almost indefinitely.
One whole year of the grammar school course may well be given to the
observations suggested in Chapter I, provided that there is no need of
hastening on to the more advanced work. The advantage of extending the
course over a whole school year is great, because such extension gives
opportunity for becoming familiar with late summer, autumn, winter,
spring, and early summer weather types, and this is far better than
attempting to crowd all the work into one short season. The interest of a
class can easily be kept up throughout a school year by means of a
progressive system of observations. It is best to vary the observations
from time to time, and to arrange them so that, beginning with the more
simple, they shall gradually become more complete and more advanced as
the year goes on. Thus, starting with temperature observations alone,
these may be continued for one or two weeks before they are supplemented
by records of wind direction and velocity. After some practice in the
observation of these two weather elements (say during one month), data as
to the state of the sky may be added. Cloud observations themselves may
well be graded during successive weeks, so that, beginning with the
simplest notes concerning amounts of cloudiness, the pupils shall
gradually advance to the point of observing, and perhaps even of
sketching, the common cloud forms and their changes. Thus an important
step will have been taken towards appreciating the need of a standard
cloud classification, which may be given later.
The addition of records of precipitation completes the list of simple
non-instrumental weather observations, and these records, as well as the
cloud records, can easily be graded, so that, during successive weeks,
every week’s work shall be different from that of every other week. In
this progression from the simpler to the more complicated observations
lies the secret of making the work attractive. Nothing will sooner check
interest in the study than the necessity of making exactly the same
observations day after day and week after week throughout the year. A
graded course of non-instrumental observation, such as is suggested, gives
a very practical general knowledge of our common weather types and
changes, and of the relations of one weather element to another. The
questions asked under the different headings in this chapter are designed
to awaken the interest of the scholars, and to call their attention to the
more important points of diurnal, cyclonic, and seasonal changes in
weather elements. The teacher will readily think of other questions which
may be suggested for the consideration of the class.
Although the non-instrumental records are of little value for future
reference, as compared with the instrumental observations, they should
nevertheless be systematically preserved by the class in their record
books. After discussion of the daily observations made by the different
scholars, or by one of their number, the records may be written upon one
of the blackboards reserved for this purpose. At the close of the day, or
the next morning, the blackboard notes should be entered in a record book
kept in the schoolroom. The teacher may guide in the discussion of the
observations; may suggest points overlooked by the scholars; may draw
comparisons between the weather conditions of other weeks and of other
days. This talking over of the observations is most important, as it never
fails to bring out much of interest.
CHAPTER II.
This work may usually be begun in the early years of the grammar school
course, as soon as the non-instrumental observations have been
satisfactorily completed. The scheme of progressive observations already
suggested may be followed to advantage in the instrumental work as well as
in the non-instrumental. It is often a good plan to have a different
scholar assigned to the task of taking the observations every day, or it
may be more advisable to divide the work, making one responsible for the
temperature observations, another for the precipitation, etc. It is well
to have the daily instrumental weather records written upon the
blackboard in the schoolroom, as already suggested in the case of the
non-instrumental observations. At the end of each day the blackboard data
should be entered in a permanent record book by some one of the scholars,
and some ingenuity can be exercised in devising the best scheme for
keeping this record. The record book should be carefully preserved in the
schoolroom, where it may be referred to by the scholars of future years
when any unusually severe storm, or a spell of excessively hot or dry
weather, or a remarkable cold wave occurs, in order that comparison with
past occurrences of a similar kind may be made. It is well to have the
record book of large size, and to have each day’s record entered across
two full pages. On the left-hand page the temperature, pressure, rainfall,
wind direction and velocity, etc., may be entered, each observation in its
proper column, the number of columns being increased according to the
increasing number of observations. The right-hand page may be left for
“Remarks.” These “Remarks” should include notes of any meteorological
phenomena which did not find a place in the columns reserved for the
regular observations, _e.g._, occurrence of hail, or frozen rain; damage
by lightning, winds, or floods; freezing up of rivers or brooks;
interruption of railroad or street-car traffic by snow, etc., and, in
general, explanatory comments on the weather conditions. Instructive
lessons may be taught as to the relation of the local weather conditions
which prevail in the vicinity of the school, and those of other portions
of the country, by comments on newspaper despatches concerning gales along
the coast or on the lakes, and resulting damage to shipping; of snow
blockades and stalled trains; of severe thunderstorms and tornadoes; of
hot waves and sunstrokes, or of cold waves and the destruction of crops or
fruits by the frost. The scholars should be encouraged to bring into the
class any comments on such phenomena as may be of interest in the work.
Such of these newspaper clippings as are of the most value may be pasted
in the space reserved for the “Remarks,” where they may be referred to by
succeeding classes; and in this space also may be pasted at the end of
each week the barograph and thermograph sheets, if these instruments are
in use at the school.
CHAPTER III.
These observations may usually be profitably undertaken in the later
grammar and in the high school years. The instruments described, while all
desirable, are by no means all necessary, and no teacher should postpone
the establishment of a course in observational meteorology for the reason
that a complete set of first-class instruments cannot be secured at the
start.
If the school is provided with a psychrometer, there will be no need of
the ordinary thermometer, because the psychrometer gives the true air
temperature. It is well, however, to have both stationary wet and dry-bulb
thermometers, in the shelter, for ordinary school use, and also a sling
psychrometer for use in the meteorological _field work_ which forms an
important part of the more advanced instrumental work in meteorology. The
sling psychrometer may, of course, be used simply as an ordinary sling
thermometer.
The simple form of mercurial barometer, without vernier and without
attached thermometer, described in Chapter II, will be found the best
barometer for general school use. The standard barometer, described in
this chapter, is too expensive and too complicated to come into extended
use in our schools. Full instructions concerning the care, the reading,
and the corrections of the standard mercurial barometer are published by
the Weather Bureau, and to these instructions teachers who have such an
instrument are referred. (See Appendix B.)
The form of table given at the end of this chapter is intended merely as a
suggestion, and not as a rigid scheme to be adopted in every school. In
using the instruments here described, practice with the maximum and
minimum thermometers (in addition to the simpler work of Chapter II) may
be given before any attempt is made to have the class use the
psychrometer. And in using the psychrometer one week may well be given to
the determination of the dew-point alone, before the wet and dry-bulb
readings are employed to determine the relative humidity. Absolute
humidity, which is not referred to in this chapter, may, if the teacher
deem it advisable, be added as another weather element for study. A
refinement in the notes on the state of the sky is suggested, viz., that
cloudiness should be recorded in tenths of the sky covered by clouds. This
is an advance over the earlier, less accurate cloud observations, and is
in line with such a progressive scheme as has been recommended. This book
is not intended to present a rigid scheme of observational work in
meteorology, alike for all schools, but rather to make suggestions for the
guidance of teachers in laying out such a course as may fit their own
cases.
Under the heading _Summary of Observations_ only a few of the most
important climatic elements have been noted. The list may easily be
extended by the addition of such data as the following: For temperature,
mean diurnal range; mean diurnal variability (the mean of the differences
between the successive daily means). For humidity, monthly mean absolute
humidity. For precipitation, the maximum daily precipitation; the number
of rainy and snowy days in every month, the number of clear, fair, and
cloudy days in every month; the mean frequency of rainfall in every month
(number of rainy days divided by the total number of days); the number of
days with thunderstorms, etc.
It is important that the monthly summaries should be discussed in the
class, and that the scholars should give verbal statements as to the
numerical results which they have obtained. In this way the work will have
a living interest, which the mere compilation of summaries does not
possess.
CHAPTER IV.
The first thing for any teacher to do who intends to establish a course in
meteorology is to secure a supply of daily weather maps. Arrangements
should be made to have them mailed regularly from the nearest
map-publishing station of the Bureau. It is important that the Saturday
morning map, which is usually not sent to schools, should be included in
the set, as the break of two days (Saturday and Sunday) in every week
seriously interferes with the value of the work that may be done on
consecutive maps. The maps should be securely fastened up in the
schoolroom or in the hall. It is advisable to keep at least two maps thus
on view all the time, in order that the scholars may be able to study the
changes from day to day by comparing the last two or three maps with one
another. As soon as they are removed from the wall, the maps should be
carefully filed away for future reference. They may be conveniently kept
in stiff brown paper folders, each month’s maps being enclosed in a
separate folder, with the name of the month and the year written on the
outside. It is a good plan to keep with the file of maps any newspaper
clippings referring to notable meteorological phenomena associated with
the conditions shown on the maps. Thus, newspaper accounts of the damage
done by a hurricane along the Atlantic Coast; of the blockades caused by a
heavy snowstorm in the Northwest; of tornadoes in the Mississippi Valley;
of hot waves and sunstrokes in our larger cities, will serve to enliven
the study of the maps, and will also help, in later references to them, to
recall interesting points that might otherwise escape the memory. It is
true that newspapers are prone to exaggerate, and that they are lamentably
inaccurate in their use of meteorological terms; but nevertheless they
may often be profitably used in such general studies as these. Besides the
complete weather map, the school will need a supply of blank weather maps,
as used by the Weather Bureau. These may usually be secured from the
nearest map-publishing station at cost price. In the case of the
preparation of illustrations for permanent class use, as suggested later,
it is advisable to employ the blank maps used as the base of the
Washington daily weather maps, and to be obtained, at cost price, on
application to the Chief of the Weather Bureau, Washington, D. C. These
are larger in size (16-1/2 by 23-3/4 inches) than the station maps, and
the paper is of a better quality. Colored illustrations with these
Washington blank maps as the base furnish an economical, simple, and
effective means of teaching elementary meteorology.
CHAPTER V.
In this chapter a series of six consecutive weather maps is taken as the
basis of the work. The study of the weather elements on such a series of
maps gives a far clearer understanding of the distribution of these
elements and of their relation one with another, than if a far larger
number of single maps are studied which do not follow one another in
regular sequence. Teachers should add to the map-drawing exercises by
giving their classes the data from other sets of maps selected from the
school files. Summer maps as well as winter ones should be used, in order
that too much emphasis may not be laid on winter conditions. The search
for the various cities in which Weather Bureau stations are established,
involved in the work of entering the data on the blank maps, furnishes
excellent practice in geography. This exercise may be varied, and practice
in the location of the different States may be given, if the teacher reads
out to the class the temperatures in different parts of the various
States, as, _e.g._, central Arizona, 34°; southwestern Tennessee, 30°;
northern Nevada, 38°, etc. As the State names are not given on the Weather
Bureau maps, such a method as this will give a very desirable familiarity
with the relative positions of the States of the Union. If the school
possesses a blackboard outline map of the United States, it may be a good
plan, if the class is small, to have one of the pupils enter the
temperatures and draw the isotherms on the board before the class, and to
let the others correct him if they see that he is going wrong. As to
irregularities in the isotherms, which may cause trouble, the officials of
the Weather Bureau vary somewhat among themselves in dealing with such
cases, and no definite rules can be laid down to fit all occasions. It is
best to select maps with few irregularities at first, and in time
experience will show how the exceptional cases may be treated.
By the scheme of coloring isothermal maps, suggested in this chapter, a
valuable series of permanent illustrations of noteworthy weather types for
class use can readily be prepared at very slight cost. For the purposes of
these colored illustrations it is best to use the large scale Washington
blank weather maps, as suggested in the preceding chapter, and to have
each map mounted on heavy cardboard after it has been colored. By means of
this mounting the maps are prevented from tearing, and can be kept smooth
and in good condition.
The scheme of coloring may be varied to suit the fancy of the scholars,
for the preparation of these permanent illustrations may well be intrusted
to those of the class who are especially interested in the work, and who
are skillful in their use of the paint brush. The work is really very
simple and needs only ordinary care. As soon as the drawing of isotherms
and the coloring of isothermal charts have been sufficiently studied, the
teacher should hang up the daily weather map each day (or a blank map with
the isotherms for the day drawn on it), and should call attention to the
temperature changes from day to day. In this way the facts of actual
temperature changes experienced by the class will be associated with the
larger temperature changes shown on the weather maps.
The sections on temperature gradients may be postponed, if the teacher
deems it advisable, until other matters of a simpler nature are passed.
The idea of rates of change is not an easy one for students to grasp, and
it is far better to postpone the consideration of this subject than to
involve the class in any confusion at this stage. It is a mistake,
however, to omit these sections altogether, as a clear conception of the
principle of rates is a valuable part of a student’s mental equipment. It
is a good plan, in the exercises on lines of temperature decrease, to
have maps prepared with _faint_ isotherms and _heavy_ lines of temperature
decrease, in order to emphasize the idea of change of temperature, in
contrast to the idea of constancy of temperature expressed by the
isotherms.
CHAPTER VI.
In the work on the wind charts it is essential to proceed very slowly, in
order that the best results may be obtained by the pupils. Some of the
aberrant wind courses, which complicate the discovery of the cyclonic and
anticyclonic spirals, may well be omitted in the case of the younger
classes, and considerable assistance in facilitating these discoveries may
be given by suggestions as to adding intermediate dotted wind arrows, in
sympathy with the observed wind directions. The anticyclonic systems are
always much more difficult to discover than the cyclonic, and care should
be taken to assist the class in this matter as much as seems necessary.
The questions in the text are merely suggestive, and are by no means as
numerous as it would be well to make them in the class. The discovery of
the spirals will probably be made by degrees. The concise formulation of
the facts discovered will furnish excellent basis for exercises in
writing.
It is interesting to note that the discussion as to whether the winds blow
circularly around, or radially in towards, centers of low pressure, which
usually comes up in every class in meteorology at some stage in the study,
was carried on in a very animated way about the middle of the present
century in this country. Two noted American meteorologists, Redfield and
Espy, and their respective followers, took opposite sides in this
controversy, Redfield maintaining at the start that the winds moved in
circles, and Espy maintaining that they followed radial courses. The truth
lay between the two.
CHAPTER VII.
The study of atmospheric pressure is not easy, because the pupils cannot
perceive the changes in pressure from day to day by their unaided senses.
Especially difficult does this study become if the class has not already
had some practice in making barometer readings. When this observational
work has not preceded the consideration of the isobaric lines of the daily
weather maps, the teacher should introduce the subject of pressure very
carefully. The experiment with the Torricellian tube will show the class
something of the reality of atmospheric pressure, and the variations in
this pressure from day to day can readily be made apparent by means of a
few barometer readings, if time cannot be spared for a regular and
continued series of barometer observations. A word may be said as to the
correction of barometric readings for local influences, in order to make
these readings comparable, if this matter has not been previously met
with, but care should be taken not to confuse the younger pupils too much
with explanations at this stage of the work. It may be well to omit this
point unless it is brought up by some pupil. The questions asked in the
text are merely suggestive. They may be added to and varied at the
discretion of the teacher.
Lines of pressure-decrease should be drawn on all isobaric charts studied
in the class, as they are highly instructive. When the isobars are near
together, these lines of pressure-decrease may be drawn heavier, to
indicate a steeper gradient. The convergence of these lines towards
regions of low pressure, and their divergence from regions of high
pressure, seen on every map on which these gradients are drawn, emphasizes
an important lesson. Before measuring rates of pressure-decrease by means
of a scale, considerable practice should be given in the study, by means
of the eye, of the rapidity or slowness of decrease of pressure, as shown
by the heavier or lighter lines of pressure-decrease. When the broad facts
of differing rates are comprehended, then the actual measurement of these
rates is a comparatively easy matter. In any case, however, an
appreciation of these rates of change is not always readily gained, even
by older scholars in the high school. It is, therefore, of prime
importance to proceed very slowly indeed at this point, and to have every
step fully understood before another step is taken.
The instructions in the text for measuring rates of pressure-decrease are,
that these rates shall be recorded as so many hundredths of an inch of
change of pressure in one latitude-degree. This is done for the sake of
simplicity. If this rate is expressed in hundredths of an inch of pressure
in a quarter of a latitude-degree of distance, the numerical value is the
same as if expressed in millimeters of pressure per latitude-degree of
distance.
CHAPTER VIII.
The fact of the prevalence of different kinds of weather over the country
at the same time is of great importance. It should be strongly emphasized
by the teacher in the course of the discussion of the maps of weather
distribution. Additional exercises of the same sort may be given to
advantage, by letting the class plot and study the weather signs taken
from any current weather map. Instructive lessons may be taught by talking
over, in the class, the different ways in which people all over the
country are affected by the character of the weather that happens to
prevail where they are.
CHAPTERS IX-XVIII.
The correlation exercises will, as a whole, teach few entirely new facts
to the brighter scholars who have faithfully completed the preceding work
in observations and in the construction and study of the daily weather
maps. These exercises do, however, lead to detailed examination and to the
careful working out of the relations which may have been previously
noticed in a general way only. They give the repeated illustration which
is necessary in order to impress firmly on the mind the lesson that the
weather map has to teach.
It is a good plan to let different scholars work out the problems for
different months. The results reached in each case should be discussed in
the class, and thus each member may have the double advantage of working
out his own problem, and of profiting by the work done by his fellows.
Throughout these exercises care should be taken to have weather maps of
all months studied. The exercise on the correlation of the velocity of the
wind with the pressure cannot be undertaken unless the work on
temperature and pressure gradients (Chapters V and VII) has been
completed.
CHAPTERS XX-XXV.
It is not expected that any one scholar can accomplish all that is here
outlined. Examples may be selected from the list, as opportunity offers,
so that each scholar shall become familiar with several problems.
Few of the problems suggested call for continuous routine observation at
fixed hours. They require, on the other hand, an intelligent examination
of ordinary weather phenomena, with special reference to discovering their
explanation. In most of the problems a small number of observations will
suffice. Under the supervision of the teacher, different problems may be
assigned to the several members of a class; or several scholars may work
on different parts of the same problem, exchanging records in order to
save time. All the scholars should have a general knowledge of the results
which have been obtained from the observations made by the other members
of their class. The teacher will use his discretion in arranging the order
of the problems, and in selecting those that are best suited to the season
in which the work is done, to the locality in which the school is
situated, and to the facilities and apparatus at command. Although the
variety of accessible problems is less in city schools than in country
schools, much may be done in the city as well as in the country.
The opportunities for carrying out such observational work vary so much in
different schools that it is impossible to give specific instructions,
which shall be available in all cases. Some general suggestions are
therefore given, which the teacher may supplement by more detailed
instructions framed to fit the particular circumstances of each case.
A review of the headings of the different problems shows that a very
general correlation exists among them, whereby the subjects of every
heading are associated with those of nearly every other. In other words,
every weather element is treated as a function of several other elements.
It follows from this that the variety of work here outlined is more
apparent than real, and that many problems which appear from their wording
to be entirely new are in large part rearrangements of problems previously
encountered.
APPENDIX B.
THE EQUIPMENT OF A METEOROLOGICAL LABORATORY.
_A._ INSTRUMENTS.
_Exposed Thermometer_ (United States Weather Bureau pattern), with brass
support, $2.75.
_Maximum and Minimum Thermometers_ (United States Weather Bureau pattern),
mounted together on one board, $6.25.
_Wet- and Dry-Bulb Thermometers_ (United States Weather Bureau pattern),
mounted on one board, complete with water cup, $6.50.
_Sling Psychrometer_ (designed by Professor C. F. Marvin, of the United
States Weather Bureau), consisting of two exposed mercurial thermometers,
mounted on an aluminum back, and provided with polished, turned hard-wood
handle and brass trimmings, $5.00.
_Sling Psychrometer_, consisting of two cylindrical bulb thermometers,
mounted one a little above the other upon a light brass frame, with a
perforated guard to protect the bulbs while swinging, but which can be
raised (by sliding upon the frame) for the purpose of moistening the linen
covering of the wet bulb. Much less liable to be broken than the Weather
Bureau pattern, $5.00.
_Rain Gauge_ (United States Weather Bureau standard), 8 inches in
diameter, complete, with measuring stick, $5.25.
_Rain Gauge_, 3 inches in diameter, with overflow and measuring stick,
$1.25.
_Wind Vane_ (United States Weather Bureau pattern), $10.00.
_Anemometer_ (United States Weather Bureau pattern), with indicator,
aluminum cups, and electrical attachment, $25.00.
The same, with painted brass cups, $23.00.
_Anemometer Register_ (United States Weather Bureau pattern), with pen and
ink attachment, $35.00.
The same, with pencil attachment (old style), $24.00.
_Aneroid Barometer_ (for meteorological work), $14.00-$16.00.
NOTE.——Much cheaper aneroids can be purchased, and may be used
to some advantage in the simpler observations in schools.
_Mercurial Barometer_ (Standard United States Weather Bureau pattern),
complete with attached thermometer, vernier, etc., $30.00-$33.00.
NOTE.——The above instruments, as used by the United States
Weather Bureau, are made by H. J. Green, 1191 Bedford Avenue,
Brooklyn, N. Y. The prices are those given in Green’s latest
catalogue.
_Mercurial Barometer._ New improved form, especially designed for school
use. Mounted on mahogany back. Scale engraved on aluminum. Divisions of
scale on metric and English systems. No vernier, $5.75.
(L. E. Knott Apparatus Co., 14 Ashburton Place, Boston, Mass.)
_Thermograph_ (designed by Dr. Daniel Draper, of New York). Consists of a
bimetallic thermometer in a case which carries a disk, with a chart upon
its axle instead of hands like the ordinary clock. A pen (resting on the
face of the disk) registers the fluctuations of temperature as the chart
is carried around. Sizes, 14 × 20 inches, $30.00; 10 × 14 inches, $15.00.
This instrument may be purchased of H. J. Green.
_Thermograph._ Self-recording thermometer (as adopted by the United States
Weather Bureau), made by Richard Frères, of Paris. Records continuously on
a sheet of paper wound around a revolving drum, which is driven by
clock-work inside. Standard size (without duty), $30.00.
_Barograph._ Self-recording barometer (as adopted by the United States
Weather Bureau), made by Richard Frères, of Paris. Similar in general
arrangement to the thermograph. Standard size (without duty), $27.60.
These last two instruments can be procured through Glaenzer Frères &
Rheinboldt, 26 & 28 Washington Place, New York City.
_Instrument Shelter_ (standard United States Weather Bureau pattern) will
hold a set of maximum and minimum thermometers, psychrometer, and a
thermograph. May be set up on top of posts driven into the ground, or may
be attached to a wall, $18.00.
_Barometer Box_, for the standard mercurial barometer. Made of mahogany,
with glass panels on front and sides; lock and key, and with fittings
complete, $8.50.
These may be purchased of H. J. Green.
_B._ TEXT-BOOKS.
_The Story of the Earth’s Atmosphere._ DOUGLAS ARCHIBALD. New York, D.
Appleton & Co., 1898. 18mo, pp. 194. 40 cents.
To be recommended to the general reader who wishes to gain some knowledge
of meteorology quickly. Not a text-book. Contains a chapter on “Flight in
the Atmosphere.”
_Elementary Meteorology._ WILLIAM MORRIS DAVIS. Boston, Ginn & Co., 1898.
8vo, pp. 355. $2.50.
The most complete of the modern text-books, and the best adapted for use
in the systematic teaching of meteorology. The modern views are presented
clearly and without the use of mathematics. Portions of it are somewhat
too advanced for school study, but teachers will find it invaluable as a
reference book in directing the laboratory work, and in answering the
questions of school classes.
_A Popular Treatise on the Winds._ WILLIAM FERREL. New York, John Wiley &
Sons, 1890. 8vo, pp. 505. $3.40.
This can hardly be regarded as a _popular_ treatise. It embodies, in
condensed and chiefly non-mathematical form, the results of Ferrel’s
researches during his long and profound study of the general circulation
and phenomena of the atmosphere. Teachers who advance far into meteorology
will find this book indispensable. It is not at all suited for general
class-room use.
_American Weather._ A. W. GREELY. New York, Dodd, Mead & Co., 1888. 8vo,
pp. 286. Out of print, but secondhand copies are probably obtainable.
Deals, as the title implies, especially with the weather phenomena of the
United States. Contains brief accounts of individual hot and cold waves,
hurricanes, blizzards and tornadoes, and gives specific data concerning
maxima and minima of temperature, precipitation, etc., in the United
States.
_Meteorology: Practical and Applied._ JOHN WILLIAM MOORE. London, F. J.
Rebman, 1894. 8vo, pp. 445. 8 shillings.
A readable book. Considerable space is given to instrumental meteorology.
Contains chapters on the climate of the British Isles and on the relations
of weather and disease in the British Isles. Especially adapted for the
use of English readers.
_Elementary Meteorology._ ROBERT H. SCOTT. International Scientific
Series. London, Kegan Paul, Trench & Co., 1885; Boston, A. A. Waterman &
Co., 1889. 8vo, pp. 410. 6 shillings.
The standard text-book in Great Britain. The author is secretary to the
Meteorological Council of the Royal Society. Fairly complete, but now
somewhat out of date in some portions. It is a useful book in a
meteorological library, but does not treat the subject in a way very
helpful to the teacher.
_Meteorology._ THOMAS RUSSELL. New York, The Macmillan Company, 1895. 8vo,
pp. 277.
Brief and incomplete as a text-book of meteorology, but containing a very
comprehensive account, fully illustrated, of rivers and floods in the
United States, and their prediction.
_Elementary Meteorology._ FRANK WALDO. New York, American Book Company,
1896. 8vo, pp. 373. 90 cents.
A compact summary. Useful to teachers as a handy reference book.
_Modern Meteorology._ FRANK WALDO. New York, Charles Scribner’s Sons,
1893. 8vo, pp. 460. $1.25.
Very complete account of meteorological apparatus and methods, and
admirable summary of recent German studies of the thermodynamics and
general motions of the atmosphere.
_C._ INSTRUCTIONS IN THE USE OF INSTRUMENTS.
_Instructions for Voluntary Observers._ 1899. 8vo, pp. 23. Brief
instructions for taking and recording observations of temperature and
precipitation with ordinary and maximum and minimum thermometers and with
the rain gauge.
_Barometers and the Measurement of Atmospheric Pressure._ C. F. MARVIN.
1894. 8vo, pp. 74. A pamphlet of information respecting the theory and
construction of barometers in general, with summary of instructions for
the care and use of the standard Weather Bureau instruments.
_Instructions for Obtaining and Tabulating Records from Recording
Instruments._ 1898. 8vo, pp. 31. Contains directions concerning the care
and use of the Richard thermograph and barograph.
NOTE.——These pamphlets are prepared under the direction of
Professor Willis L. Moore, Chief of the United States Weather
Bureau, and are published, under authority of the Secretary of
Agriculture, by the Weather Bureau. They will be found the best
guides in making observations, the care of instruments, etc.
_D._ JOURNALS, ETC.
_Monthly Weather Review._ Prepared under the direction of Willis L. Moore,
Chief of Weather Bureau, Professor Cleveland Abbe, Editor. United States
Department of Agriculture, Weather Bureau, Washington, D. C. 10 cents a
copy.
An invaluable publication for teachers and students alike. Contains
complete meteorological summaries for each month; accounts of all notable
storms, cold and hot waves, etc.; and a large number of articles on a wide
range of meteorological subjects. The charts show the tracks of areas of
high and low pressure which crossed the United States during the month,
the total precipitation, sea-level pressure, temperature and surface
winds, percentage of sunshine, etc., for the month. Other charts are also
frequently added.
_The Journal of School Geography._ Professor Richard E. Dodge, Teachers
College, Columbia University, New York City, Editor. Publication Office,
41 No. Queen Street, Lancaster, Pa. Ten numbers a year. $1.00 per annum.
A monthly journal devoted to the interests of the common school teacher of
geography. Contains numerous articles and notes on meteorological and
climatological subjects.
_Science._ Edited by Professor J. McK. Cattell, Columbia University, New
York City, New York, The Macmillan Company. Weekly. $5.00 per annum.
Devoted to the advancement of all sciences. Contains brief _Current Notes
on Meteorology_, which summarize the more important meteorological
publications.
_Monthly Bulletins of the Climate and Crop Service of the Weather Bureau._
These _Bulletins_ are issued every month at the central office of the
Weather Bureau in each State, under the direction of the Section Director
of the Climate and Crop Service in that State. They contain meteorological
data for the month, and frequently notes of interest. The annual summaries
are especially valuable.
_E._ CHARTS.
_Daily Weather Maps._ These are published at the central office of the
Weather Bureau in Washington, and at eighty-four other stations of the
Bureau throughout the United States. It is best to have the daily maps
sent from the nearest map-publishing station, and not from Washington, as
the delay in the latter case is often so great that much of the immediate
value of the maps is lost.
_Climate and Crop Bulletin of the United States Weather Bureau._
Washington, D. C. Monthly.
Chart showing, by means of small maps, the actual precipitation,
departures from normal precipitation, departures from normal temperature,
and maximum and minimum temperatures. Also a printed summary of the
weather and of the crop conditions in the different sections of the United
States. Issued on the first of each month.
_Snow and Ice Chart of the United States Weather Bureau._ Washington, D.
C. Weekly during the winter season.
Based on data from regular Weather Bureau stations, supplemented by
reports from selected voluntary observers. Shows, by shading, the area
covered with snow at 8 P.M. each Tuesday during the winter, and by lines,
the depth of snow in inches. Explanatory tables and text accompany the
chart.
_Storm Bulletin of the United States Weather Bureau._ Washington, D. C.
Issued at irregular intervals.
Charts, with text, illustrating the history of individual notable storms.
_Pilot Chart of the North Atlantic and North Pacific Oceans._ Hydrographic
Office, Bureau of Equipment, Department of the Navy, Washington, D. C.
Monthly. Price 10 cents a copy.
Shows calms and prevailing winds, ocean currents, regions of fog and
equatorial rains, the positions of icebergs and wrecks, steamship and
sailing routes, storm tracks, magnetic variation, etc. Also gives isobars
and isotherms and a forecast for the month succeeding the date of
publication, and a review of the weather over the oceans for the preceding
month. Supplementary charts are occasionally issued.
_Rainfall and Snow of the United States as compiled to the End of 1891,
with Annual, Seasonal, Monthly, and other Charts._ MARK W. HARRINGTON.
United States Department of Agriculture. Weather Bureau, Bulletin C,
Washington, D. C. 1894. Atlas, 18 × 24 inches. Charts 23. Text, 4-80 pp.
Contains twenty-three charts as follows: Monthly rainfall, seasonal
rainfall, annual rainfall, monthly snowfall, monthly maxima of rainfall,
rainy seasons, details of rainfall, details of occurrence of
thunderstorms. Well adapted to serve as illustrations for use in the
class-room. The text is explanatory, and is published separately in quarto
form.
_Rainfall of the United States, with Annual, Seasonal, and other Charts._
ALFRED J. HENRY. United States Department of Agriculture, Weather Bureau,
Bulletin D, Washington, D. C. 1897. 9-1/4 × 11-1/2 inches. Pp. 58. Charts
10. Plates III.
A more recent publication than the preceding one, the averages having been
compiled to the end of 1896. The charts are smaller than most of those in
Bulletin C, and therefore not so well adapted for class-room illustration.
The chart of mean annual precipitation is the latest and best published.
The rainfall of the crop-growing season receives separate treatment, and
is illustrated by means of two charts. The discussion in the text is
excellent.
_F._ METEOROLOGICAL TABLES.
_Smithsonian Meteorological Tables._ Smithsonian Miscellaneous
Collections, 844. Washington, D. C. 1893. 8vo. Pp. 262.
A very complete set of tables.
_Handbook of Meteorological Tables._ H. A. HAZEN (of the United States
Weather Bureau). Washington, D. C. 1888. 8vo. Pp. 127. $1.50.
Contains forty-seven tables, comprising all that are needed by the working
meteorologist. Includes tables for Fahrenheit and Centigrade conversions,
for barometric hypsometry and reduction to sea level, for the
psychrometer, etc.
_Tables for Obtaining the Temperature of the Dew-Point, Relative Humidity,
etc._ United States Department of Agriculture, Weather Bureau, Washington,
D. C. 1897. 8vo. Pp. 29.
These are the tables now in use by the Weather Bureau.
_G._ ILLUSTRATIONS.
_Classification of Clouds for the Weather Observers of the Hydrographic
Office._ Hydrographic Office, Bureau of Navigation, Department of the
Navy, Washington, D. C. 1897. Sheet of twelve colored views. Price 40
cents. In book form, with descriptive text, $1.00.
An excellent set of cloud views, classified according to the
_International Nomenclature_. The text describes the various cloud forms
and shows their value as weather prognostics. An attractive addition to
the furnishings of a schoolroom.
_Selected List of Cloud Photographs and Lantern Slides._
Consists of twenty-eight photographs, and the same number of lantern
slides, of the typical cloud forms, selected by the present writer from
the collection in the Physical Geography Laboratory of Harvard University.
The photographs (20 cents each, mounted) and slides (40 cents each) may be
purchased of E. E. Howell, 612 17th Street, N. W., Washington, D. C. A
description of these views was published in the _American Meteorological
Journal_ for July, 1894 (Boston, Mass., Ginn & Company).
_Photographs._ Photographs of miscellaneous meteorological phenomena, such
as snow and ice storms, damage by storm-waves or high winds, wind-blown
trees, lightning, etc., may often be purchased of local dealers. They add
to the attractiveness of a schoolroom and furnish excellent illustrations
in teaching.
_H._ GENERAL.
The following _Bulletins_ of the Weather Bureau may be found useful as
reference books:
No. 1. _Notes on the Climate and Meteorology of Death Valley, California._
MARK W. HARRINGTON. 8vo. 1892. Pp. 50.
No. 8. _Report on the Climatology of the Cotton Plant._ P. H. MELL. 8vo.
1893. Pp. 68.
No. 10. _The Climate of Chicago._ H. A. HAZEN. 8vo. 1893. Pp. 137.
No. 11. _Report of the International Meteorological Congress held at
Chicago, III., Aug. 21-24, 1893._ 8vo. Pt. I, 1894, pp. 206. Pt. II, 1895,
pp. 583. Pt. III, 1896, pp. 772. Pt. IV, not yet issued.
No. 15. _Protection from Lightning._ ALEXANDER MCADIE. 8vo. 1895. Pp. 26.
No. 17. _The Work of the Weather Bureau in Connection with the Rivers of
the United States._ WILLIS L. MOORE. 8vo. 1896. Pp. 106.
No. 19. _Report on the Relative Humidity of Southern New England and Other
Localities._ A. J. HENRY. 8vo. 1896. Pp. 23.
No. 20. _Storms, Storm Tracks and Weather Forecasting._ FRANK H. BIGELOW.
8vo. 1897. Pp. 87.
No. 21. _Climate, of Cuba._ Also, _A Note on the Weather of Manila._ W. F.
R. PHILLIPS. 8vo. 1898. Pp. 23.
No. 23. _Frost: When to expect it and how to lessen the Injury therefrom._
W. H. HAMMON. 8vo. 1899. Pp. 37.
No. 25. _Weather Forecasting: Some Facts Historical, Practical, and
Theoretical._ WILLIS L. MOORE. 8vo. 1899. Pp. 16.
No. 26. _Lightning and the Electricity of the Air._ In two parts. A. G.
MCADIE and A. J. HENRY. 8vo. 1899. Pp. 74.
The following miscellaneous publications of the Weather Bureau may also
prove of value.
_Injury from Frost and Methods of Protection._ W. H. HAMMON. 8vo. 1896.
Pp. 12.
_Some Climatic Features of the Arid Regions._ WILLIS L. MOORE. 8vo. 1896.
Pp. 19.
_Investigation of the Cyclonic Circulation and the Translatory Movement of
the West Indian Hurricanes._ The late REV. BENITO VIÑES, S. J. 8vo. 1898.
Pp. 34.
Requests for weather maps, _Bulletins_, and other publications of the
Weather Bureau should be sent to the Chief of the Weather Bureau,
Washington, D. C. All requests are dealt with on their merits, and in
cases where it is deemed that effective use will be made of the
publications they are usually sent free of charge.
INDEX.
A.
Anemometer, 38-41.
Aneroid barometer, 23, 24.
Anticyclones, 76.
———— and pressure changes, 141.
———— and temperature, 104-106.
———— and weather, 109-112.
———— and wind circulation, 98-100.
———— form and dimensions of, 96-98.
———— progression of, 111, 112.
———— tracks of, 111, 112.
B.
Backing winds, 118.
Barograph, 36, 37.
———— records, 37, 38.
Barometer, aneroid, 23, 24.
———— corrections, 33, 34.
———— mercurial, 19-23, 32, 33.
———— reduction to freezing, 143, 144, 166, 167.
Barometer reduction to sea level, 144, 145, 168-170.
Buran, 75, 76.
Buys-Ballot’s Law, 99.
C.
Cherrapunjee, rainfall at, 138.
Clouds and upper air currents, 136, 137.
Clouds as weather prognostics, 137.
———— forms and changes of, 136.
———— movements of, 41-43, 46, 95, 136, 137.
Clouds, observations of, 5, 9, 41-43, 45, 46.
Cold wave, 62, 75, 76, 103, 106.
Cold-wave forecasts, 63.
Correlations of weather elements, 91-113.
Cyclones, 76.
———— and pressure changes, 141.
———— and temperature, 104-106.
———— and weather, 109-111, 113, 114.
———— and wind circulation, 98-100.
———— form and dimensions of, 96-98.
———— progression of, 111, 112.
———— tracks of, 111, 113.
———— tropical, 106.
———— velocity of, 112, 113.
D.
Dew, 134, 136.
———— point, 30.
———— ———— tables, 142, 143, 146-155.
Diurnal variation of temperature, 125-127.
Diurnal variation of wind velocity, 130.
Doldrums, 29.
E.
Equipment of a meteorological laboratory, 186.
Evaporation, 29.
F.
Fahrenheit, 12, 13.
Ferrel’s Law, 93.
Forecasts, cold-wave, 63.
———— weather, 49, 114-124.
Franklin, Benjamin, 114, 115.
Frost, 135.
———— warnings, 135.
G.
Galileo, 12, 19.
Gradients, pressure, 82-85.
———— temperature, 64-70.
———— vertical temperature, 129.
H.
Humidity, 29, 132-134.
———— diurnal variation of, 133.
———— relative, 30, 32, 45, 133.
———— relative, and wind direction, 133.
———— tables, 143, 156-165.
Hurricane, 100.
I.
Inversions of temperature, 129.
Isobaric charts, 76-82, 85, 95, 96.
Isobars, 77-82, 121.
Isothermal charts, 63, 68-70.
Isotherms, 55-57, 121.
L.
Land and sea breezes, 3, 131, 132.
Loomis, 97, 113.
M.
Meteorological tables, 146-170.
Mistral, 75.
Monsoons, 100.
Mountain and valley winds, 131.
N.
Nephoscope, 41-43.
O.
Observational meteorology, problems in, 125-141.
Observations, advanced instrumental, 26-46.
Observations, cloud, 5, 9, 41-43.
———— elementary instrumental, 11-26.
Observations, non-instrumental, 1-10.
Observations, rainfall, 9, 10, 26.
———— state of sky, 5, 9.
———— temperature, 1-3, 25.
———— wind, 3-5, 8, 9, 25.
P.
Pampero, 76, 104.
Pascal, 21.
Precipitation, 7, 9, 10, 138, 139.
Pressure and wind direction, 91-93.
———— and wind velocity, 93-96.
———— atmospheric, 19-21.
———— charts, 76-83.
———— cyclonic variation of, 140, 141.
———— decrease with altitude, 139, 140.
———— diurnal variation of, 140, 141.
———— gradient, 82-85.
Prevailing westerly winds, 93, 95, 96, 112, 113.
Psychrometer, 28.
———— sling, 31.
Purga, 75.
R.
Rain, see Precipitation.
———— heavy, 138, 139.
———— gauge, 15-17.
Rainfall records, 17, 18, 26.
S.
Sensible temperatures, 29, 30.
Sirocco, 103, 104, 133, 134.
Sling psychrometer, 31.
Smudges, 135.
State of sky, 5, 9, 45.
Suggestions to teachers, 171.
T.
Temperature charts, 58-60.
———— distribution, 51-63.
———— diurnal range, 125-127.
———— forecasts, 116.
———— gradient, 64-70.
Temperature gradient, vertical, 129.
———— inversions, 129.
———— maximum and minimum, 45.
———— mean, 43, 45.
———— observations, 1-3, 8-10, 25, 43, 45.
———— range, 45, 125-127.
———— sensible, 29, 30.
———— vertical distribution of, 128, 129.
Thermograph, 34-36.
———— records, 35, 36.
Thermometer, 12.
———— attached, 33.
———— maximum and minimum, 26-28.
———— shelter, 13, 14.
———— wet- and dry-bulb, 28, 30, 31.
Torricelli, 19, 20.
Trade winds, 93.
V.
Veering winds, 118.
Vernier, 33.
Vertical temperature gradient, 129.
W.
Water vapor, 28.
Weather, 85-90.
———— and wind direction, 106-109.
———— changes, sequence of, 113, 114.
———— charts, 85-90.
Weather forecasts, 49, 114-124.
———— map data, 90.
———— maps, 47-51.
———— prognostics, 137.
———— signs, 85.
———— temperate zone, 88-90.
———— torrid zone, 88-90.
Wind charts, 70-75.
———— direction and pressure, 91-93.
———— ———— and relative humidity, 133.
———— ———— and temperature, 101-104.
———— ———— and weather, 106-109.
———— ———— forecasts of, 118.
———— observations, 3-5, 25, 40, 41.
———— rose, 103, 108, 109.
———— vane, 15.
———— velocity, 3, 40, 41, 45.
———— ———— and pressure, 93-96.
———— ———— diurnal variation of, 130.
———— ———— forecasts of, 118.
———— ———— scale, 3.
Winds around cyclones and anticyclones, 98-100.
Winds, mountain and valley, 131, 132.
———— prevailing westerly, 93, 95-96, 112, 113.
Winds, trade, 93.
Woeikof, 69.
* * * * *
TRANSCRIBER’S AMENDMENTS
Transcriber’s Note:
Blank pages have been deleted.
Some illustrations have been moved.
The footnotes have been coalesced and moved so as to follow the
referencing paragraph.
The publisher’s inadvertent omissions of important punctuation have been
corrected.
Some wide tables have been re-formatted to narrower equivalents with some
words replaced with commonly known abbreviations and possibly a key.
The table on page 44 has been flipped around a diagonal axis so that the
original column headings are now row headings.
The following list indicates any additional changes made. The page number
represents that of the original publication and applies in this etext
except for footnotes and illustrations since they may have been moved.
Key: {<from>}[<to>]:
Page Change
6 Than {}[the] day before yesterday?
62 reduction of temperature{ to}[ ]from 16° to 36°.
75 general relation between winds and cold {wave}[waves]
159 | 47 | 44 | 42 | {29}[39] | 36 | 34 | 31 | 53
162 {103}[108] | 97 | 93 | 90 | 87 | 83 | 80 |
170 <Multiple unrecorded corrections.>
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