| t | Difference between the dry and wet thermometers (t-t′). | t |
| (Dry ther.) | 0°.5 | 1°.0 | 1°.5 | 2°.0 | 2°.5 | 3°.0 | 3°.5 | 4°.0 | 4°.5 | 5°.0 | 5°.5 | 6°.0 | (Dry ther.) |
| 20 | 18 | 17 | 15 | 13 | 10 | 8 | 5 | 2 | -2 | -6 | -12 | -19 | 20 |
| 21 | 19 | 18 | 16 | 14 | 12 | 9 | 7 | 4 | 0 | -4 | -8 | -15 | 21 |
| 22 | 20 | 19 | 17 | 15 | 13 | 11 | 8 | 6 | +2 | -1 | -6 | -11 | 22 |
| 23 | 22 | 20 | 18 | 16 | 14 | 12 | 10 | 7 | 4 | +1 | -3 | -8 | 23 |
| 24 | 23 | 21 | 19 | 18 | 16 | 14 | 11 | 9 | 6 | 3 | -1 | -5 | 24 |
| 25 | 24 | 22 | 21 | 19 | 17 | 15 | 13 | 11 | 8 | 5 | +2 | -2 | 25 |
| 26 | 25 | 23 | 22 | 20 | 18 | 16 | 14 | 12 | 10 | 7 | 4 | 0 | 26 |
| 27 | 26 | 24 | 23 | 21 | 20 | 18 | 16 | 14 | 11 | 9 | 6 | +3 | 27 |
| 28 | 27 | 25 | 24 | 22 | 21 | 19 | 17 | 15 | 13 | 11 | 8 | 5 | 28 |
| 29 | 28 | 26 | 25 | 24 | 22 | 20 | 19 | 17 | 14 | 12 | 10 | 7 | 29 |
| 30 | 29 | 27 | 26 | 25 | 23 | 22 | 20 | 18 | 16 | 14 | 11 | 9 | 30 |
| 31 | 30 | 29 | 27 | 26 | 24 | 23 | 21 | 19 | 18 | 15 | 13 | 11 | 31 |
| 32 | 31 | 30 | 28 | 27 | 26 | 24 | 22 | 21 | 19 | 17 | 15 | 13 | 32 |
| 33 | 31 | 31 | 29 | 28 | 26 | 25 | 23 | 22 | 19 | 18 | 16 | 14 | 33 |
| 34 | 32 | 32 | 30 | 29 | 27 | 26 | 24 | 24 | 21 | 20 | 18 | 16 | 34 |
| 35 | 33 | 32 | 31 | 30 | 29 | 28 | 26 | 25 | 23 | 22 | 20 | 18 | 35 |
| 36 | 35 | 34 | 32 | 31 | 30 | 29 | 27 | 26 | 24 | 23 | 21 | 19 | 36 |
| 37 | 36 | 35 | 33 | 32 | 31 | 30 | 28 | 27 | 26 | 24 | 22 | 21 | 37 |
| 38 | 37 | 36 | 34 | 33 | 32 | 31 | 30 | 28 | 27 | 26 | 24 | 22 | 38 |
| 39 | 38 | 37 | 35 | 34 | 33 | 32 | 30 | 29 | 28 | 27 | 25 | 24 | 39 |
| 40 | 39 | 38 | 36 | 35 | 34 | 33 | 31 | 30 | 29 | 28 | 26 | 25 | 40 |
| 41 | 40 | 39 | 37 | 36 | 35 | 34 | 32 | 32 | 30 | 29 | 28 | 26 | 41 |
| 42 | 41 | 40 | 39 | 38 | 36 | 35 | 34 | 33 | 31 | 30 | 29 | 27 | 42 |
| 43 | 42 | 41 | 40 | 39 | 37 | 36 | 35 | 34 | 32 | 31 | 30 | 29 | 43 |
| 44 | 43 | 42 | 41 | 40 | 38 | 37 | 36 | 35 | 33 | 32 | 31 | 30 | 44 |
| 45 | 44 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 32 | 31 | 45 |
| 46 | 45 | 44 | 43 | 42 | 41 | 40 | 38 | 37 | 36 | 35 | 33 | 32 | 46 |
| 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 47 |
| 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 38 | 37 | 36 | 35 | 48 |
| 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 39 | 38 | 37 | 36 | 49 |
| 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 38 | 37 | 50 |
| 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 39 | 38 | 51 |
| 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 52 |
| 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 53 |
| 54 | 53 | 52 | 51 | 50 | 50 | 49 | 47 | 46 | 45 | 44 | 43 | 42 | 54 |
| 55 | 54 | 53 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 44 | 43 | 55 |
| 56 | 55 | 54 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 56 |
| 57 | 56 | 55 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 57 |
| 58 | 57 | 56 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 58 |
| 59 | 58 | 57 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 59 |
| 60 | 59 | 58 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 60 |
| 61 | 60 | 59 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 61 |
| 62 | 61 | 60 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 52 | 62 |
| 63 | 62 | 61 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 55 | 54 | 53 | 63 |
| 64 | 63 | 62 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 56 | 55 | 54 | 64 |
| 65 | 64 | 63 | 63 | 62 | 61 | 60 | 59 | 59 | 58 | 57 | 56 | 55 | 65 |
| 66 | 65 | 64 | 64 | 63 | 62 | 61 | 60 | 60 | 59 | 58 | 57 | 56 | 66 |
| 67 | 67 | 66 | 65 | 64 | 63 | 62 | 61 | 61 | 60 | 59 | 58 | 57 | 67 |
| 68 | 68 | 67 | 66 | 65 | 64 | 63 | 62 | 62 | 61 | 60 | 59 | 58 | 68 |
| 69 | 69 | 68 | 67 | 66 | 65 | 64 | 63 | 63 | 62 | 61 | 60 | 59 | 69 |
| 70 | 70 | 69 | 68 | 67 | 67 | 66 | 65 | 64 | 63 | 62 | 61 | 61 | 70 |
| 71 | 71 | 70 | 69 | 68 | 68 | 67 | 66 | 65 | 64 | 63 | 62 | 62 | 71 |
| 72 | 72 | 71 | 70 | 69 | 69 | 68 | 67 | 66 | 65 | 64 | 63 | 63 | 72 |
| 73 | 73 | 72 | 71 | 70 | 70 | 69 | 68 | 67 | 66 | 66 | 65 | 64 | 73 |
| 74 | 74 | 73 | 72 | 71 | 71 | 70 | 69 | 68 | 67 | 67 | 66 | 65 | 74 |
| 75 | 75 | 74 | 73 | 72 | 72 | 71 | 70 | 69 | 68 | 68 | 67 | 66 | 75 |
| 76 | 76 | 75 | 74 | 73 | 73 | 72 | 71 | 70 | 69 | 69 | 68 | 67 | 76 |
| 77 | 77 | 76 | 75 | 74 | 74 | 73 | 72 | 71 | 70 | 70 | 69 | 68 | 77 |
| 78 | 78 | 77 | 76 | 75 | 75 | 74 | 73 | 72 | 71 | 71 | 70 | 69 | 78 |
| 79 | 79 | 78 | 77 | 76 | 76 | 75 | 74 | 73 | 72 | 72 | 71 | 70 | 79 |
| 80 | 80 | 79 | 78 | 77 | 77 | 76 | 75 | 74 | 73 | 73 | 72 | 72 | 80 |
| t. | 0°.5 | 1°.0 | 1°.5 | 2°.0 | 2°.5 | 3°.0 | 3°.5 | 4°.0 | 4°.5 | 5°.0 | 5°.5 | 6°.0 | t. |
Table I.—Temperature of the Dew-Point, in Degrees Fahrenheit.
| t | Difference between the dry and wet thermometers (t-t′). | t |
| (Dry ther.) | 6°.0 | 6°.5 | 7°.0 | 7°.5 | 8°.0 | 8°.5 | 9°.0 | 9°.5 | 10°.0 | 10°.5 | 11°.0 | 11°.5 | 12°.0 | (Dry ther.) |
| 19 | -25 | | | | | | | | | | | | | 19 |
| 20 | -19 | -32 | | | | | | | | | | | | 20 |
| 21 | -15 | -24 | -47 | | | | | | | | | | | 21 |
| 22 | -11 | -19 | -31 | | | | | | | | | | | 22 |
| 23 | -8 | -14 | -24 | -45 | | | | | | | | | | 23 |
| 24 | -5 | -10 | -18 | -30 | | | | | | | | | | 24 |
| 25 | -2 | -7 | -13 | -22 | -42 | | | | | | | | | 25 |
| 26 | 0 | -4 | -9 | -17 | -28 | | | | | | | | | 26 |
| 27 | +3 | -1 | -6 | -12 | -20 | -37 | | | | | | | | 27 |
| 28 | 5 | +1 | -3 | -8 | -15 | -25 | -54 | | | | | | | 28 |
| 29 | 7 | 4 | 0 | -4 | -10 | -18 | -32 | | | | | | | 29 |
| 30 | 9 | 6 | +2 | -2 | -6 | -13 | -22 | -43 | | | | | | 30 |
| 31 | 11 | 8 | 5 | +1 | -3 | -8 | -15 | -27 | | | | | | 31 |
| 32 | 13 | 10 | 7 | 4 | 0 | -4 | -10 | -18 | -33 | | | | | 32 |
| 33 | 14 | 12 | 9 | 6 | +3 | -1 | -6 | -12 | -22 | -44 | | | | 33 |
| 34 | 16 | 14 | 11 | 8 | 6 | +2 | -2 | -8 | -15 | -27 | | | | 34 |
| 35 | 18 | 15 | 13 | 10 | 8 | 5 | +1 | -4 | -9 | -18 | -32 | | | 35 |
| 36 | 19 | 17 | 15 | 12 | 10 | 8 | 4 | 0 | -5 | -12 | -20 | -42 | | 36 |
| 37 | 21 | 19 | 17 | 14 | 12 | 9 | 6 | +3 | -2 | -6 | -14 | -25 | -52 | 37 |
| 38 | 22 | 20 | 19 | 16 | 14 | 11 | 9 | 6 | +2 | -2 | -8 | -16 | -29 | 38 |
| 39 | 24 | 22 | 20 | 18 | 16 | 14 | 11 | 8 | 5 | +1 | -4 | -10 | -18 | 39 |
| 40 | 25 | 23 | 22 | 20 | 18 | 16 | 13 | 11 | 8 | 4 | 0 | -5 | -12 | 40 |
| 41 | 26 | 25 | 23 | 21 | 20 | 17 | 15 | 13 | 10 | 7 | +4 | -1 | -6 | 41 |
| 42 | 27 | 26 | 24 | 23 | 21 | 19 | 18 | 15 | 12 | 10 | 7 | +3 | -2 | 42 |
| 43 | 29 | 27 | 26 | 24 | 23 | 21 | 19 | 17 | 14 | 12 | 9 | 6 | +2 | 43 |
| 44 | 30 | 28 | 27 | 26 | 24 | 22 | 20 | 18 | 16 | 14 | 12 | 9 | 6 | 44 |
| 45 | 31 | 30 | 28 | 27 | 25 | 24 | 22 | 20 | 18 | 16 | 13 | 11 | 8 | 45 |
| 46 | 32 | 31 | 30 | 28 | 27 | 25 | 24 | 22 | 20 | 18 | 16 | 13 | 11 | 46 |
| 47 | 33 | 32 | 31 | 29 | 28 | 26 | 25 | 23 | 22 | 20 | 18 | 15 | 13 | 47 |
| 48 | 35 | 33 | 32 | 30 | 29 | 28 | 26 | 25 | 23 | 21 | 20 | 17 | 15 | 48 |
| 49 | 36 | 34 | 33 | 32 | 31 | 29 | 28 | 26 | 25 | 23 | 21 | 19 | 17 | 49 |
| 50 | 37 | 35 | 34 | 33 | 32 | 31 | 29 | 28 | 26 | 24 | 23 | 21 | 19 | 50 |
| 51 | 38 | 37 | 36 | 34 | 33 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 21 | 51 |
| 52 | 40 | 38 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 28 | 26 | 24 | 23 | 52 |
| 53 | 41 | 39 | 38 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 28 | 26 | 24 | 53 |
| 54 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 27 | 26 | 54 |
| 55 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 28 | 55 |
| 56 | 44 | 43 | 42 | 41 | 40 | 39 | 37 | 36 | 34 | 33 | 32 | 30 | 29 | 56 |
| 57 | 46 | 45 | 44 | 42 | 41 | 40 | 39 | 37 | 36 | 35 | 33 | 32 | 30 | 57 |
| 58 | 47 | 46 | 45 | 44 | 42 | 41 | 40 | 39 | 37 | 36 | 35 | 33 | 32 | 58 |
| 59 | 48 | 47 | 46 | 45 | 44 | 43 | 41 | 40 | 39 | 38 | 36 | 35 | 33 | 59 |
| 60 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 41 | 40 | 39 | 38 | 36 | 35 | 60 |
| 61 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 39 | 38 | 36 | 61 |
| 62 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 43 | 42 | 41 | 39 | 38 | 62 |
| 63 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 43 | 42 | 41 | 39 | 63 |
| 64 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 43 | 42 | 41 | 64 |
| 65 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 43 | 42 | 65 |
| 66 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 46 | 45 | 44 | 66 |
| 67 | 57 | 56 | 55 | 55 | 54 | 53 | 52 | 51 | 50 | 48 | 47 | 46 | 45 | 67 |
| 68 | 58 | 57 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 47 | 46 | 68 |
| 69 | 59 | 58 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 69 |
| 70 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 70 |
| 71 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 55 | 54 | 53 | 52 | 51 | 71 |
| 72 | 63 | 62 | 61 | 60 | 59 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 72 |
| 73 | 64 | 63 | 62 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 73 |
| 74 | 65 | 64 | 63 | 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 74 |
| 75 | 66 | 65 | 64 | 64 | 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 56 | 75 |
| 76 | 67 | 66 | 65 | 65 | 64 | 63 | 62 | 61 | 61 | 60 | 59 | 58 | 57 | 76 |
| 77 | 68 | 67 | 67 | 66 | 65 | 64 | 63 | 62 | 62 | 61 | 60 | 59 | 58 | 77 |
| 78 | 69 | 68 | 68 | 67 | 66 | 66 | 65 | 64 | 63 | 62 | 61 | 60 | 59 | 78 |
| 79 | 70 | 69 | 69 | 68 | 67 | 67 | 66 | 65 | 64 | 63 | 62 | 61 | 61 | 79 |
| 80 | 72 | 71 | 70 | 69 | 68 | 68 | 67 | 66 | 65 | 64 | 63 | 62 | 62 | 80 |
| t. | 6°.0 | 6°.5 | 7°.0 | 7°.5 | 8°.0 | 8°.5 | 9°.0 | 9°.5 | 10°.0 | 10°.5 | 11°.0 | 11°.5 | 12°.0 | t. |
Table I.—Temperature of the Dew-Point, in Degrees Fahrenheit.
| t | Difference between the dry and wet thermometers (t-t′). | t |
| (Dry ther.) | 12°.0 | 12°.5 | 13°.0 | 13°.5 | 14°.0 | 14°.5 | 15°.0 | 15°.5 | 16°.0 | 16°.5 | 17°.0 | 17°.5 | 18°.0 | (Dry ther.) |
| 40 | -12 | -22 | -44 | | | | | | | | | | | 40 |
| 41 | -6 | -13 | -25 | | | | | | | | | | | 41 |
| 42 | -2 | -7 | -15 | -28 | | | | | | | | | | 42 |
| 43 | +2 | -3 | -8 | -17 | -33 | | | | | | | | | 43 |
| 44 | 6 | +1 | -4 | -10 | -19 | -40 | | | | | | | | 44 |
| 45 | 8 | 5 | 0 | -4 | -11 | -22 | -48 | | | | | | | 45 |
| 46 | 11 | 8 | +4 | 0 | -5 | -13 | -24 | | | | | | | 46 |
| 47 | 13 | 10 | 7 | +3 | -1 | -6 | -14 | -27 | | | | | | 47 |
| 48 | 15 | 12 | 10 | 6 | +2 | -2 | -8 | -16 | -30 | | | | | 48 |
| 49 | 17 | 14 | 12 | 9 | 6 | +2 | -3 | -9 | -18 | -35 | | | | 49 |
| 50 | 19 | 16 | 14 | 12 | 9 | 5 | +1 | -4 | -10 | -20 | -42 | | | 50 |
| 51 | 21 | 18 | 17 | 14 | 11 | 8 | 5 | 0 | -5 | -12 | -22 | -52 | | 51 |
| 52 | 23 | 21 | 19 | 16 | 14 | 11 | 8 | +4 | 0 | -6 | -13 | -25 | | 52 |
| 53 | 24 | 22 | 20 | 18 | 16 | 14 | 11 | 8 | +4 | -1 | -6 | -14 | -28 | 53 |
| 54 | 26 | 24 | 22 | 20 | 18 | 16 | 13 | 10 | 7 | +3 | -2 | -8 | -16 | 54 |
| 55 | 28 | 26 | 24 | 22 | 20 | 18 | 16 | 13 | 10 | 7 | +3 | -2 | -8 | 55 |
| 56 | 29 | 27 | 26 | 24 | 22 | 20 | 18 | 15 | 13 | 10 | 6 | +2 | -2 | 56 |
| 57 | 30 | 29 | 28 | 26 | 24 | 22 | 20 | 18 | 15 | 13 | 10 | 6 | +2 | 57 |
| 58 | 32 | 30 | 29 | 27 | 26 | 24 | 22 | 20 | 18 | 15 | 12 | 9 | 6 | 58 |
| 59 | 33 | 32 | 31 | 29 | 27 | 26 | 24 | 22 | 20 | 18 | 15 | 12 | 9 | 59 |
| 60 | 35 | 33 | 32 | 30 | 29 | 27 | 26 | 24 | 22 | 20 | 18 | 15 | 12 | 60 |
| 61 | 36 | 35 | 33 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 20 | 18 | 15 | 61 |
| 62 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 20 | 18 | 62 |
| 63 | 39 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 20 | 63 |
| 64 | 41 | 39 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 24 | 22 | 64 |
| 65 | 42 | 41 | 40 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 24 | 65 |
| 66 | 44 | 43 | 41 | 40 | 38 | 37 | 35 | 34 | 32 | 31 | 30 | 28 | 26 | 66 |
| 67 | 45 | 44 | 43 | 41 | 40 | 39 | 37 | 36 | 34 | 32 | 31 | 30 | 28 | 67 |
| 68 | 46 | 45 | 44 | 43 | 42 | 40 | 39 | 38 | 36 | 34 | 33 | 31 | 30 | 68 |
| 69 | 48 | 47 | 46 | 45 | 43 | 42 | 40 | 39 | 38 | 36 | 34 | 33 | 32 | 69 |
| 70 | 49 | 48 | 47 | 46 | 45 | 43 | 42 | 41 | 39 | 38 | 36 | 35 | 33 | 70 |
| 71 | 51 | 49 | 48 | 47 | 46 | 45 | 43 | 42 | 41 | 39 | 38 | 36 | 35 | 71 |
| 72 | 52 | 51 | 50 | 49 | 47 | 46 | 45 | 44 | 43 | 41 | 40 | 38 | 37 | 72 |
| 73 | 53 | 52 | 51 | 50 | 49 | 48 | 46 | 45 | 44 | 43 | 41 | 40 | 38 | 73 |
| 74 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 43 | 41 | 40 | 74 |
| 75 | 56 | 55 | 54 | 53 | 52 | 50 | 49 | 48 | 47 | 45 | 44 | 43 | 42 | 75 |
| 76 | 57 | 56 | 55 | 54 | 53 | 52 | 50 | 49 | 48 | 47 | 46 | 45 | 43 | 76 |
| 77 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 46 | 45 | 77 |
| 78 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 | 47 | 78 |
| 79 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 49 | 48 | 79 |
| 80 | 62 | 61 | 60 | 59 | 58 | 57 | 56 | 55 | 54 | 53 | 52 | 51 | 50 | 80 |
| t. | 12°.0 | 12°.5 | 13°.0 | 13°.5 | 14°.0 | 14°.5 | 15°.0 | 15°.5 | 16°.0 | 16°.5 | 17°.0 | 17°.5 | 18°.0 | t. |
Table I.—Temperature of the Dew-Point, in Degrees Fahrenheit.
| t | Difference between the dry and wet thermometers (t-t′). | t |
| (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 | (Dry ther.) |
| 55 | -8 | | | | | | | | | | | | | 55 |
| 56 | -2 | -19 | | | | | | | | | | | | 56 |
| 57 | +2 | -10 | -48 | | | | | | | | | | | 57 |
| 58 | 6 | -3 | -22 | | | | | | | | | | | 58 |
| 59 | 9 | +1 | -12 | | | | | | | | | | | 59 |
| 60 | 12 | 5 | -5 | -25 | | | | | | | | | | 60 |
| 61 | 15 | 9 | 0 | -14 | | | | | | | | | | 61 |
| 62 | 18 | 12 | +5 | -6 | -28 | | | | | | | | | 62 |
| 63 | 20 | 15 | 9 | 0 | -14 | | | | | | | | | 63 |
| 64 | 22 | 18 | 12 | +4 | -6 | -32 | | | | | | | | 64 |
| 65 | 24 | 20 | 15 | 9 | 0 | -16 | | | | | | | | 65 |
| 66 | 26 | 22 | 18 | 12 | +4 | -7 | -34 | | | | | | | 66 |
| 67 | 28 | 24 | 20 | 15 | 9 | -1 | -16 | | | | | | | 67 |
| 68 | 30 | 26 | 23 | 18 | 12 | +4 | -7 | -37 | | | | | | 68 |
| 69 | 32 | 28 | 25 | 20 | 15 | 8 | 0 | -17 | | | | | | 69 |
| 70 | 33 | 30 | 27 | 23 | 19 | 12 | +5 | -7 | -39 | | | | | 70 |
| 71 | 35 | 32 | 29 | 25 | 21 | 16 | 9 | 0 | -17 | | | | | 71 |
| 72 | 37 | 33 | 31 | 27 | 23 | 18 | 13 | +5 | -6 | -39 | | | | 72 |
| 73 | 38 | 35 | 32 | 29 | 25 | 21 | 16 | 10 | 0 | -16 | | | | 73 |
| 74 | 40 | 37 | 34 | 31 | 28 | 24 | 19 | 13 | +6 | -6 | -37 | | | 74 |
| 75 | 42 | 39 | 36 | 32 | 30 | 26 | 22 | 16 | 10 | 0 | -16 | | | 75 |
| 76 | 43 | 41 | 38 | 34 | 32 | 28 | 24 | 20 | 14 | +6 | -6 | -34 | | 76 |
| 77 | 45 | 42 | 40 | 36 | 33 | 30 | 26 | 22 | 17 | 11 | +1 | -14 | | 77 |
| 78 | 47 | 44 | 41 | 38 | 35 | 32 | 28 | 24 | 20 | 14 | 7 | -4 | -30 | 78 |
| 79 | 48 | 46 | 43 | 40 | 37 | 34 | 31 | 27 | 23 | 18 | 11 | +2 | -13 | 79 |
| 80 | 50 | 47 | 45 | 42 | 39 | 36 | 32 | 29 | 25 | 21 | 15 | 8 | -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 I.—Temperature of the Dew-Point, in Degrees Fahrenheit.
| t | Difference between the dry and wet thermometers (t-t′). | t |
| (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 | (Dry ther.) |
| 80 | 79 | 77 | 76 | 74 | 73 | 72 | 70 | 68 | 67 | 65 | 63 | 62 | 80 |
| 81 | 80 | 78 | 77 | 75 | 74 | 73 | 71 | 70 | 68 | 66 | 65 | 63 | 81 |
| 82 | 81 | 79 | 78 | 77 | 75 | 74 | 72 | 71 | 69 | 68 | 66 | 64 | 82 |
| 83 | 82 | 80 | 79 | 78 | 76 | 75 | 73 | 72 | 70 | 69 | 67 | 65 | 83 |
| 84 | 83 | 81 | 80 | 79 | 77 | 76 | 74 | 73 | 71 | 70 | 68 | 67 | 84 |
| 85 | 84 | 82 | 81 | 80 | 78 | 77 | 75 | 74 | 72 | 71 | 69 | 68 | 85 |
| 86 | 85 | 83 | 82 | 81 | 79 | 78 | 76 | 75 | 73 | 72 | 71 | 69 | 86 |
| 87 | 86 | 84 | 83 | 82 | 80 | 79 | 78 | 76 | 74 | 73 | 72 | 70 | 87 |
| 88 | 87 | 85 | 84 | 83 | 81 | 80 | 79 | 77 | 75 | 74 | 73 | 71 | 88 |
| 89 | 88 | 86 | 85 | 84 | 82 | 81 | 80 | 78 | 76 | 76 | 74 | 72 | 89 |
| 90 | 89 | 87 | 86 | 85 | 84 | 82 | 81 | 79 | 78 | 77 | 75 | 74 | 90 |
| 91 | 90 | 88 | 87 | 86 | 85 | 83 | 82 | 80 | 79 | 78 | 76 | 75 | 91 |
| 92 | 91 | 89 | 88 | 87 | 86 | 84 | 83 | 82 | 80 | 79 | 77 | 76 | 92 |
| 93 | 92 | 91 | 89 | 88 | 87 | 85 | 84 | 83 | 81 | 80 | 78 | 77 | 93 |
| 94 | 93 | 92 | 90 | 89 | 88 | 86 | 85 | 84 | 82 | 81 | 80 | 78 | 94 |
| 95 | 94 | 93 | 91 | 90 | 89 | 87 | 86 | 85 | 83 | 82 | 81 | 79 | 95 |
| 96 | 95 | 94 | 92 | 91 | 90 | 88 | 87 | 86 | 84 | 83 | 82 | 80 | 96 |
| 97 | 96 | 95 | 93 | 92 | 91 | 90 | 88 | 87 | 86 | 84 | 83 | 81 | 97 |
| 98 | 97 | 96 | 94 | 93 | 92 | 91 | 89 | 88 | 87 | 85 | 84 | 83 | 98 |
| 99 | 98 | 97 | 95 | 94 | 93 | 92 | 90 | 89 | 88 | 86 | 85 | 84 | 99 |
| 100 | 99 | 98 | 96 | 95 | 94 | 93 | 91 | 90 | 89 | 87 | 86 | 85 | 100 |
| 101 | 100 | 99 | 97 | 96 | 95 | 94 | 92 | 91 | 90 | 88 | 87 | 86 | 101 |
| 102 | 101 | 100 | 98 | 97 | 96 | 95 | 93 | 92 | 91 | 90 | 88 | 87 | 102 |
| 103 | 102 | 101 | 99 | 98 | 97 | 96 | 94 | 93 | 92 | 91 | 89 | 88 | 103 |
| 104 | 103 | 102 | 100 | 99 | 98 | 97 | 96 | 94 | 93 | 92 | 90 | 89 | 104 |
| 105 | 104 | 103 | 101 | 100 | 99 | 98 | 97 | 95 | 94 | 93 | 91 | 90 | 105 |
| 106 | 105 | 104 | 102 | 101 | 100 | 99 | 98 | 96 | 95 | 94 | 93 | 91 | 106 |
| 107 | 106 | 105 | 103 | 102 | 101 | 100 | 99 | 97 | 96 | 95 | 94 | 92 | 107 |
| 108 | 107 | 106 | 104 | 103 | 102 | 101 | 100 | 98 | 97 | 96 | 95 | 93 | 108 |
| 109 | 108 | 107 | 105 | 104 | 103 | 102 | 101 | 99 | 98 | 97 | 96 | 94 | 109 |
| 110 | 109 | 108 | 107 | 105 | 104 | 103 | 102 | 101 | 99 | 98 | 97 | 96 | 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. |