Chapter 6 of 16 · 9225 words · ~46 min read

CHAPTER VI

THE ADVANTAGE OF TAKING WEATHER OBSERVATIONS AND APPLYING THEM TO ONE’S PERSONAL NEEDS

FORECASTS MADE FROM THE ANEROID BAROMETER—COLDS PREVENTED BY MOISTENING AIR IN LIVING ROOMS—A CRIMINAL HANGED AND AN INNOCENT MAN FREED BY WEATHER RECORDS

=Observations from Kites.= It is strange that the Chinese, who have been flying kites many thousand years, should not have made improvements in the primitive construction of these devices. It remained for Wendham, in 1866, to perceive the advantage of superimposing two or more planes, one above the other, for the purpose of securing a larger area of sustaining surface. After examining Figure 3 almost any one can build an efficient kite. Heights of two to three thousand feet may be reached by using cable-laid twine No. 24, but in order to gain great altitudes pianoforte wire must be used. Soft pine is the best and most available material. Spruce is stronger, but more difficult to secure. The sticks should be straight-grained. The cloth may be silk or the stronger and finer grades of cotton. It should be torn, not cut. The ends will then be true and square with the fiber of the cloth. Kites are used not only to secure weather observations, but they have been used to draw sleds in the Arctic region, and to draw wagons and boats. By adjusting the points at which the pulling cords are attached to the boat an ingenious sailor is able to proceed nearly at right angles to the direction of the wind.

[Illustration: FIG. 3.—STANDARD WEATHER BUREAU KITE.]

When it is known that a box kite having only sixty square feet of sustaining surface, flying at a considerable height, may lift a person of ordinary size, one is impressed with the idea that vessels of commerce might employ kites of large dimensions to increase the speed of sailing ships. The kites would fly in a stratum whose velocity is not restricted by friction with the surface of the water.

To launch a kite: run out about one hundred and fifty feet of the cord or wire while the kite is held by an assistant, who should give the kite a toss upward in the direction in which it must go. It is important that it be cast off directly in line with the wind. If the wind is light it may be necessary to run a short distance with a long line out in order to effect a launching.

=Voluntary Weather Observers.= There are more than three thousand voluntary or coöperating observers in the U. S. Weather Bureau. They receive no compensation other than the publications of the Bureau. They are required to read their instruments but once each day, as maximum and minimum thermometers record the highest and the lowest temperatures since they were last read and set. About sunset is the most satisfactory time for making the readings, since the thermometers will then show both the extremes for the past twenty-four hours. As a rule but one voluntary observer is accepted for a county. They are furnished without charge with maximum and minimum thermometers, instrument shelters and rain gauges, but not with wind vanes, anemometers for recording direction and velocity of wind, or barometers. But those who desire to become expert in forecasting the weather, as all may who study the chapter on forecasting, should equip themselves with an aneroid barometer, so that they may note the changes in the pressure of the air.

[Illustration: FIG. 5.—Comparison of the Thermometer Scales.]

COMPARISON OF THERMOMETER SCALES

A little study of the accompanying information and diagram will enable any one to form a clear idea of the various thermometer scales and to convert temperatures from one scale to another.

_Table of fixed points._

-----------+----------------+----------------+-----------------+ Scale. | Temperature of | Temperature of | No. of degrees | | melting ice. | boiling water. | between melting | | | | ice and boiling | | | | water. | -----------+----------------+----------------+-----------------+ Centigrade | 0 | 100 | 100 | Reaumur | 0 | 80 | 80 | Fahrenheit | 32 | 212 | 180 | -----------+----------------+----------------+-----------------+

Only Fahrenheit and Centigrade scales are in general use, and the accompanying plate is designed to enable observers to convert temperature readings from one scale to the other without resorting to a mathematical formula.

For accurate and precise reductions between the different scales the following rules should be used:

1. To convert Fahrenheit to Centigrade: Subtract 32 and multiply by five ninths.

2. To convert Centigrade to Fahrenheit: Multiply by nine fifths and add 32.

3. To convert Fahrenheit to Reaumur: Subtract 32 and multiply by four ninths.

4. To convert Reaumur to Fahrenheit: Multiply by nine fourths and add 32.

5. To convert Centigrade to Reaumur: Multiply by four fifths.

6. To convert Reaumur to Centigrade: Multiply by five fourths.

An instrument shelter (Figure 4) is employed to screen off the direct and reflected sunshine, and to keep the thermometers dry. This shelter is a box with louvered sides, constructed in such form that there is a free circulation of air through it. It should be exposed in an open space as far away from buildings as may be convenient, or on a housetop, and be as free from shadows as possible. If such position cannot be secured, then place it on the north side of a building.

[Illustration: FIG. 6.—Dry and Wet Bulb Thermometers.]

=Comparison of Centigrade and Fahrenheit.= Only Fahrenheit and Centigrade are in general use. Figure 5 is designed to enable observers to convert temperature readings from one scale to the other without resorting to a mathematical formula. For precise reductions the following rules apply:

To convert Fahrenheit to Centigrade: Subtract 32 and multiply by five ninths.

To convert Centigrade to Fahrenheit: Multiply by nine fifths and add 32.

=Humidity Affects Health and Complexion.= The importance to health of maintaining a proper humidity in living quarters during the winter months and during all months in the arid and semi-arid regions of the West is not fully appreciated. Each habitation should be supplied with one to several hygrometers (Fig. 6), and frequent readings should be taken of the dry and the wet bulb thermometers so as to be familiar with the conditions under which one is living.

RELATIVE HUMIDITY TABLES

Temperature Readings in Degrees Fahrenheit. Relative Humidity Readings in Per Cent. Barometric Pressure 29.0 inches.

(Part 1 of 7) ============+======================================================+ | DIFFERENCE IN DEGREES FAHRENHEIT BETWEEN WET | READINGS | AND DRY BULB THERMOMETERS. | OF DRY BULB +----+----+----+----+----+----+----+----+----+----+----+ THERMOMETER | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | ------------+----+----+----+----+----+----+----+----+----+----+----+ 20 | 85 | 70 | 56 | 42 | 28 | 14 | | | | | | 21 | 86 | 71 | 57 | 44 | 30 | 17 | 3 | | | | | 22 | 86 | 72 | 59 | 45 | 32 | 19 | 7 | | | | | 23 | 87 | 73 | 60 | 47 | 34 | 22 | 10 | | | | | 24 | 87 | 74 | 61 | 49 | 36 | 24 | 12 | 0 | | | | | | | | | | | | | | | | 25 | 87 | 75 | 63 | 50 | 38 | 27 | 15 | 4 | | | | 26 | 88 | 75 | 64 | 52 | 40 | 29 | 18 | 7 | | | | 27 | 88 | 76 | 65 | 53 | 42 | 31 | 20 | 9 | | | | 28 | 88 | 77 | 66 | 55 | 44 | 33 | 23 | 12 | 2 | | | 29 | 89 | 78 | 67 | 56 | 45 | 35 | 25 | 15 | 5 | | | | | | | | | | | | | | | 30 | 89 | 78 | 68 | 57 | 47 | 37 | 27 | 17 | 8 | | | 31 | 89 | 79 | 69 | 58 | 49 | 39 | 29 | 20 | 10 | 1 | | 32 | 90 | 79 | 69 | 60 | 50 | 41 | 31 | 22 | 13 | 4 | | 33 | 90 | 80 | 71 | 61 | 52 | 42 | 33 | 24 | 16 | 7 | | 34 | 90 | 81 | 72 | 62 | 53 | 44 | 35 | 27 | 18 | 9 | 1 | | | | | | | | | | | | | 35 | 91 | 82 | 73 | 64 | 55 | 46 | 37 | 29 | 20 | 12 | 4 | 36 | 91 | 82 | 73 | 65 | 56 | 48 | 39 | 31 | 23 | 14 | 6 | 37 | 91 | 83 | 74 | 66 | 58 | 49 | 41 | 33 | 25 | 17 | 9 | 38 | 91 | 83 | 75 | 67 | 59 | 51 | 43 | 35 | 27 | 19 | 12 | 39 | 92 | 84 | 76 | 68 | 60 | 52 | 44 | 37 | 29 | 21 | 14 | | | | | | | | | | | | | 40 | 92 | 84 | 76 | 68 | 61 | 53 | 46 | 38 | 31 | 23 | 16 | 41 | 92 | 84 | 77 | 69 | 62 | 54 | 47 | 40 | 33 | 26 | 18 | 42 | 92 | 85 | 77 | 70 | 62 | 55 | 48 | 41 | 34 | 28 | 21 | 43 | 92 | 85 | 78 | 70 | 63 | 56 | 49 | 43 | 36 | 29 | 23 | 44 | 93 | 85 | 78 | 71 | 64 | 57 | 51 | 44 | 37 | 31 | 24 | | | | | | | | | | | | | 45 | 93 | 86 | 79 | 71 | 65 | 58 | 52 | 45 | 39 | 33 | 26 | 46 | 93 | 86 | 79 | 72 | 65 | 59 | 53 | 46 | 40 | 34 | 28 | 47 | 93 | 86 | 79 | 73 | 66 | 60 | 54 | 47 | 41 | 35 | 29 | 48 | 93 | 87 | 80 | 73 | 67 | 60 | 54 | 48 | 42 | 36 | 31 | 49 | 93 | 87 | 80 | 74 | 67 | 61 | 55 | 49 | 43 | 37 | 32 | ------------+----+----+----+----+----+----+----+----+----+----+----+

(Part 2 of 7) ============+================================================= | DIFFERENCE IN DEGREES FAHRENHEIT BETWEEN WET READINGS | AND DRY BULB THERMOMETERS. OF DRY BULB +----+----+----+----+----+----+----+----+----+---- THERMOMETER | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 ------------+----+----+----+----+----+----+----+----+----+---- 20 | | | | | | | | | | 21 | | | | | | | | | | 22 | | | | | | | | | | 23 | | | | | | | | | | 24 | | | | | | | | | | | | | | | | | | | | 25 | | | | | | | | | | 26 | | | | | | | | | | 27 | | | | | | | | | | 28 | | | | | | | | | | 29 | | | | | | | | | | | | | | | | | | | | 30 | | | | | | | | | | 31 | | | | | | | | | | 32 | | | | | | | | | | 33 | | | | | | | | | | 34 | | | | | | | | | | | | | | | | | | | | 35 | | | | | | | | | | 36 | | | | | | | | | | 37 | 1 | | | | | | | | | 38 | 4 | | | | | | | | | 39 | 7 | | | | | | | | | | | | | | | | | | | 40 | 9 | 2 | | | | | | | | 41 | 11 | 5 | | | | | | | | 42 | 14 | 7 | 0 | | | | | | | 43 | 16 | 9 | 3 | | | | | | | 44 | 18 | 12 | 5 | | | | | | | | | | | | | | | | | 45 | 20 | 14 | 8 | 2 | | | | | | 46 | 22 | 16 | 10 | 4 | | | | | | 47 | 23 | 17 | 12 | 6 | 1 | | | | | 48 | 25 | 19 | 14 | 8 | 3 | | | | | 49 | 26 | 21 | 15 | 10 | 5 | | | | | ------------+----+----+----+----+----+----+----+----+----+----

RELATIVE HUMIDITY TABLES—Continued

Temperature Readings in Degrees Fahrenheit. Relative Humidity Readings in Per Cent. Barometric Pressure 29.0 inches.

(Part 3 of 7) ============+======================================================+ | DIFFERENCE IN DEGREES FAHRENHEIT BETWEEN WET | READINGS | AND DRY BULB THERMOMETERS. | OF DRY BULB +----+----+----+----+----+----+----+----+----+----+----+ THERMOMETER | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | ------------+----+----+----+----+----+----+----+----+----+----+----+ 50 | 93 | 87 | 81 | 74 | 68 | 62 | 56 | 50 | 44 | 39 | 33 | 51 | 94 | 87 | 81 | 75 | 69 | 63 | 57 | 51 | 45 | 40 | 35 | 52 | 94 | 88 | 81 | 75 | 69 | 63 | 58 | 52 | 46 | 41 | 36 | 53 | 94 | 88 | 82 | 75 | 70 | 64 | 58 | 53 | 47 | 42 | 37 | 54 | 94 | 88 | 82 | 76 | 70 | 65 | 59 | 54 | 48 | 43 | 38 | | | | | | | | | | | | | 55 | 94 | 88 | 82 | 76 | 71 | 65 | 60 | 55 | 49 | 44 | 39 | 56 | 94 | 88 | 82 | 77 | 71 | 66 | 61 | 55 | 50 | 45 | 40 | 57 | 94 | 88 | 83 | 77 | 72 | 66 | 61 | 56 | 51 | 46 | 41 | 58 | 94 | 89 | 83 | 77 | 72 | 67 | 62 | 57 | 52 | 47 | 42 | 59 | 94 | 89 | 83 | 78 | 73 | 68 | 63 | 58 | 53 | 48 | 43 | | | | | | | | | | | | | 60 | 94 | 89 | 84 | 78 | 73 | 68 | 63 | 58 | 53 | 49 | 44 | 61 | 94 | 89 | 84 | 79 | 74 | 68 | 64 | 59 | 54 | 50 | 45 | 62 | 94 | 89 | 84 | 79 | 74 | 69 | 64 | 60 | 55 | 50 | 46 | 63 | 95 | 90 | 84 | 79 | 74 | 70 | 65 | 60 | 56 | 51 | 47 | 64 | 95 | 90 | 85 | 79 | 75 | 70 | 66 | 61 | 56 | 52 | 48 | | | | | | | | | | | | | 65 | 95 | 90 | 85 | 80 | 75 | 70 | 66 | 62 | 57 | 53 | 48 | 66 | 95 | 90 | 85 | 80 | 76 | 71 | 66 | 62 | 58 | 53 | 49 | 67 | 95 | 90 | 85 | 80 | 76 | 71 | 67 | 62 | 58 | 54 | 50 | 68 | 95 | 90 | 85 | 81 | 76 | 72 | 67 | 63 | 59 | 55 | 51 | 69 | 95 | 90 | 86 | 81 | 77 | 72 | 68 | 64 | 59 | 55 | 51 | | | | | | | | | | | | | 70 | 95 | 90 | 86 | 81 | 77 | 72 | 68 | 64 | 60 | 56 | 52 | 71 | 95 | 90 | 86 | 82 | 77 | 73 | 69 | 64 | 60 | 56 | 53 | 72 | 95 | 91 | 86 | 82 | 78 | 73 | 69 | 65 | 61 | 57 | 53 | 73 | 95 | 91 | 86 | 82 | 78 | 73 | 69 | 65 | 61 | 58 | 54 | 74 | 95 | 91 | 86 | 82 | 78 | 74 | 70 | 66 | 62 | 58 | 54 | | | | | | | | | | | | | 75 | 96 | 91 | 87 | 82 | 78 | 74 | 70 | 66 | 63 | 59 | 55 | 76 | 96 | 91 | 87 | 83 | 78 | 74 | 70 | 67 | 63 | 59 | 55 | 77 | 96 | 91 | 87 | 83 | 79 | 75 | 71 | 67 | 63 | 60 | 56 | 78 | 96 | 91 | 87 | 83 | 79 | 75 | 71 | 67 | 64 | 60 | 57 | 79 | 96 | 91 | 87 | 83 | 79 | 75 | 71 | 68 | 64 | 60 | 57 | ------------+----+----+----+----+----+----+----+----+----+----+----+

(Part 4 of 7) ============+================================================= | DIFFERENCE IN DEGREES FAHRENHEIT BETWEEN WET READINGS | AND DRY BULB THERMOMETERS. OF DRY BULB +----+----+----+----+----+----+----+----+----+---- THERMOMETER | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 ------------+----+----+----+----+----+----+----+----+----+---- 50 | 28 | 22 | 17 | 12 | 7 | 2 | | | | 51 | 29 | 24 | 19 | 14 | 9 | 4 | | | | 52 | 30 | 25 | 20 | 15 | 10 | 6 | 0 | | | 53 | 32 | 27 | 22 | 17 | 12 | 7 | 3 | | | 54 | 33 | 28 | 23 | 18 | 14 | 9 | 5 | 0 | | | | | | | | | | | | 55 | 34 | 29 | 25 | 20 | 15 | 11 | 6 | 2 | | 56 | 35 | 31 | 26 | 21 | 17 | 12 | 8 | 4 | | 57 | 36 | 32 | 27 | 23 | 18 | 14 | 10 | 5 | 1 | 58 | 38 | 33 | 28 | 24 | 20 | 15 | 11 | 7 | 3 | 59 | 39 | 34 | 30 | 25 | 21 | 17 | 13 | 9 | 5 | 1 | | | | | | | | | | 60 | 40 | 35 | 31 | 27 | 22 | 18 | 14 | 10 | 6 | 2 61 | 40 | 36 | 32 | 28 | 24 | 20 | 16 | 12 | 8 | 4 62 | 41 | 37 | 33 | 29 | 25 | 21 | 17 | 13 | 9 | 6 63 | 42 | 38 | 34 | 30 | 26 | 22 | 18 | 14 | 11 | 7 64 | 43 | 39 | 35 | 31 | 27 | 23 | 20 | 16 | 12 | 9 | | | | | | | | | | 65 | 44 | 40 | 36 | 32 | 28 | 25 | 21 | 17 | 13 | 10 66 | 45 | 41 | 37 | 33 | 29 | 26 | 22 | 18 | 15 | 11 67 | 46 | 42 | 38 | 34 | 30 | 27 | 23 | 20 | 16 | 13 68 | 47 | 43 | 39 | 35 | 31 | 28 | 24 | 21 | 17 | 14 69 | 47 | 44 | 40 | 36 | 32 | 29 | 25 | 22 | 19 | 15 | | | | | | | | | | 70 | 48 | 44 | 40 | 37 | 33 | 30 | 26 | 23 | 20 | 17 71 | 49 | 45 | 41 | 38 | 34 | 31 | 27 | 24 | 21 | 18 72 | 49 | 46 | 42 | 39 | 35 | 32 | 28 | 25 | 22 | 19 73 | 50 | 46 | 43 | 40 | 36 | 33 | 29 | 26 | 23 | 20 74 | 51 | 47 | 44 | 40 | 37 | 34 | 30 | 27 | 24 | 21 | | | | | | | | | | 75 | 51 | 48 | 44 | 41 | 38 | 34 | 31 | 28 | 25 | 22 76 | 52 | 48 | 45 | 42 | 38 | 35 | 32 | 29 | 26 | 23 77 | 52 | 49 | 46 | 42 | 39 | 36 | 33 | 30 | 27 | 24 78 | 53 | 50 | 46 | 43 | 40 | 37 | 34 | 31 | 28 | 25 79 | 54 | 50 | 47 | 44 | 41 | 37 | 34 | 31 | 29 | 26 ------------+----+----+----+----+----+----+----+----+----+----

RELATIVE HUMIDITY TABLES—Continued

Temperature Readings in Degrees Fahrenheit. Relative Humidity Readings in Per Cent. Barometric Pressure 29.0 inches.

(Part 5 of 7) ============+======================================================+ | DIFFERENCE IN DEGREES FAHRENHEIT BETWEEN WET | READINGS | AND DRY BULB THERMOMETERS. | OF DRY BULB +----+----+----+----+----+----+----+----+----+----+----+ THERMOMETER | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | ------------+----+----+----+----+----+----+----+----+----+----+----+ 80 | 96 | 91 | 87 | 83 | 79 | 76 | 72 | 68 | 64 | 61 | 57 | 82 | 96 | 92 | 88 | 84 | 80 | 76 | 72 | 69 | 65 | 62 | 58 | 84 | 96 | 92 | 88 | 84 | 80 | 77 | 73 | 70 | 66 | 63 | 59 | 86 | 96 | 92 | 88 | 85 | 81 | 77 | 74 | 70 | 67 | 63 | 60 | 88 | 96 | 92 | 88 | 85 | 81 | 78 | 74 | 71 | 67 | 64 | 61 | | | | | | | | | | | | | 90 | 96 | 92 | 89 | 85 | 81 | 78 | 75 | 71 | 68 | 65 | 62 | 92 | 96 | 92 | 89 | 85 | 82 | 78 | 75 | 72 | 69 | 65 | 62 | 94 | 96 | 93 | 89 | 86 | 82 | 79 | 75 | 72 | 69 | 66 | 63 | 96 | 96 | 93 | 89 | 86 | 82 | 79 | 76 | 73 | 70 | 67 | 64 | 98 | 96 | 93 | 89 | 86 | 83 | 79 | 76 | 73 | 70 | 67 | 64 | | | | | | | | | | | | | 100 | 96 | 93 | 90 | 86 | 83 | 80 | 77 | 74 | 71 | 68 | 65 | 102 | 96 | 93 | 90 | 86 | 83 | 80 | 77 | 74 | 71 | 68 | 65 | 104 | 97 | 93 | 90 | 87 | 84 | 80 | 77 | 74 | 72 | 69 | 66 | 106 | 97 | 93 | 90 | 87 | 84 | 81 | 78 | 75 | 72 | 69 | 66 | 108 | 97 | 93 | 90 | 87 | 84 | 81 | 78 | 75 | 72 | 70 | 67 | | | | | | | | | | | | | 110 | 97 | 95 | 90 | 87 | 84 | 81 | 78 | 76 | 73 | 70 | 67 | 112 | 97 | 94 | 90 | 87 | 84 | 82 | 79 | 76 | 73 | 70 | 68 | 114 | 97 | 94 | 91 | 88 | 85 | 82 | 79 | 76 | 74 | 71 | 68 | 116 | 97 | 94 | 91 | 88 | 85 | 82 | 79 | 77 | 74 | 71 | 69 | 118 | 97 | 94 | 91 | 88 | 85 | 82 | 79 | 77 | 74 | 72 | 69 | | | | | | | | | | | | | 120 | 97 | 94 | 91 | 88 | 85 | 82 | 80 | 77 | 74 | 72 | 69 | 122 | 97 | 94 | 91 | 88 | 85 | 83 | 80 | 77 | 75 | 72 | 70 | 124 | 97 | 94 | 91 | 88 | 86 | 83 | 80 | 78 | 75 | 73 | 70 | 126 | 97 | 94 | 91 | 89 | 86 | 83 | 81 | 78 | 75 | 73 | 71 | 128 | 97 | 94 | 91 | 89 | 86 | 83 | 81 | 78 | 76 | 73 | 71 | | | | | | | | | | | | | 130 | 97 | 94 | 92 | 89 | 86 | 84 | 81 | 78 | 76 | 74 | 71 | 132 | 97 | 94 | 92 | 89 | 86 | 84 | 81 | 79 | 76 | 74 | 72 | 134 | 97 | 94 | 92 | 89 | 86 | 84 | 81 | 79 | 76 | 74 | 72 | 136 | 97 | 94 | 92 | 89 | 87 | 84 | 82 | 79 | 77 | 74 | 72 | 138 | 97 | 94 | 92 | 89 | 87 | 84 | 82 | 79 | 77 | 75 | 72 | | | | | | | | | | | | | 140 | 97 | 95 | 92 | 89 | 87 | 84 | 82 | 80 | 77 | 75 | 73 | ------------+----+----+----+----+----+----+----+----+----+----+----+

(Part 6 of 7) ============+======================================================+ | DIFFERENCE IN DEGREES FAHRENHEIT BETWEEN WET | READINGS | AND DRY BULB THERMOMETERS. | OF DRY BULB +----+----+----+----+----+----+----+----+----+----+----+ THERMOMETER | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | ------------+----+----+----+----+----+----+----+----+----+----+----+ 80 | 54 | 51 | 47 | 44 | 41 | 38 | 35 | 32 | 29 | 27 | 24 | 82 | 55 | 52 | 49 | 46 | 43 | 40 | 37 | 34 | 31 | 28 | 25 | 84 | 56 | 53 | 50 | 47 | 44 | 41 | 38 | 35 | 32 | 30 | 27 | 86 | 57 | 54 | 51 | 48 | 45 | 42 | 39 | 37 | 34 | 31 | 29 | 88 | 58 | 55 | 52 | 49 | 46 | 43 | 41 | 38 | 35 | 33 | 30 | | | | | | | | | | | | | 90 | 59 | 56 | 53 | 50 | 47 | 44 | 42 | 39 | 37 | 34 | 32 | 92 | 59 | 57 | 54 | 51 | 48 | 45 | 43 | 40 | 38 | 35 | 33 | 94 | 60 | 57 | 54 | 52 | 49 | 46 | 44 | 41 | 39 | 36 | 34 | 96 | 61 | 58 | 55 | 53 | 50 | 47 | 45 | 42 | 40 | 37 | 35 | 98 | 61 | 59 | 56 | 53 | 51 | 48 | 46 | 43 | 41 | 39 | 36 | | | | | | | | | | | | | 100 | 62 | 59 | 57 | 54 | 52 | 49 | 47 | 44 | 42 | 40 | 37 | 102 | 63 | 60 | 57 | 55 | 52 | 50 | 47 | 45 | 43 | 41 | 38 | 104 | 63 | 61 | 58 | 56 | 53 | 51 | 48 | 46 | 44 | 41 | 39 | 106 | 64 | 61 | 59 | 56 | 54 | 51 | 49 | 47 | 45 | 42 | 40 | 108 | 64 | 62 | 59 | 57 | 54 | 52 | 50 | 47 | 45 | 43 | 41 | | | | | | | | | | | | | 110 | 65 | 62 | 60 | 57 | 55 | 53 | 50 | 48 | 46 | 44 | 42 | 112 | 65 | 63 | 60 | 58 | 56 | 53 | 51 | 49 | 47 | 45 | 43 | 114 | 66 | 63 | 61 | 59 | 56 | 54 | 52 | 50 | 48 | 45 | 43 | 116 | 66 | 64 | 61 | 59 | 57 | 55 | 52 | 50 | 48 | 46 | 44 | 118 | 67 | 64 | 62 | 60 | 57 | 55 | 53 | 51 | 49 | 47 | 45 | | | | | | | | | | | | | 120 | 67 | 65 | 62 | 60 | 58 | 56 | 54 | 51 | 49 | 47 | 46 | 122 | 67 | 65 | 63 | 61 | 58 | 56 | 54 | 52 | 50 | 48 | 46 | 124 | 68 | 65 | 63 | 61 | 59 | 57 | 55 | 53 | 51 | 49 | 47 | 126 | 68 | 66 | 64 | 62 | 59 | 57 | 55 | 53 | 51 | 49 | 47 | 128 | 69 | 66 | 64 | 62 | 60 | 58 | 56 | 54 | 52 | 50 | 48 | | | | | | | | | | | | | 130 | 69 | 67 | 65 | 62 | 60 | 58 | 56 | 54 | 52 | 50 | 49 | 132 | 69 | 67 | 65 | 63 | 61 | 59 | 57 | 55 | 53 | 51 | 49 | 134 | 70 | 67 | 65 | 63 | 61 | 59 | 57 | 55 | 53 | 51 | 50 | 136 | 70 | 68 | 66 | 64 | 61 | 59 | 58 | 56 | 54 | 52 | 50 | 138 | 70 | 68 | 66 | 64 | 62 | 60 | 58 | 56 | 54 | 52 | 51 | | | | | | | | | | | | | 140 | 71 | 68 | 66 | 64 | 62 | 60 | 58 | 56 | 55 | 53 | 51 | ------------+----+----+----+----+----+----+----+----+----+----+----+

(Part 7 of 7) ============+======================================= | DIFFERENCE IN DEGREES FAHRENHEIT READINGS | BETWEEN WET AND DRY BULB THERMOMETERS. OF DRY BULB +----+----+----+----+----+----+----+---- THERMOMETER | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 ------------+----+----+----+----+----+----+----+---- 80 | 21 | 18 | 16 | 13 | 11 | 8 | 6 | 4 82 | 23 | 20 | 18 | 15 | 13 | 10 | 8 | 6 84 | 25 | 22 | 20 | 17 | 15 | 12 | 10 | 8 86 | 26 | 24 | 21 | 19 | 17 | 14 | 12 | 10 88 | 28 | 25 | 23 | 21 | 18 | 16 | 14 | 12 | | | | | | | | 90 | 29 | 27 | 24 | 22 | 20 | 18 | 16 | 14 92 | 30 | 28 | 26 | 24 | 22 | 19 | 17 | 15 94 | 32 | 29 | 27 | 25 | 23 | 21 | 19 | 17 96 | 33 | 31 | 29 | 26 | 24 | 22 | 20 | 18 98 | 34 | 32 | 30 | 28 | 26 | 24 | 22 | 20 | | | | | | | | 100 | 35 | 33 | 31 | 29 | 27 | 25 | 23 | 21 102 | 36 | 34 | 32 | 30 | 28 | 26 | 24 | 22 104 | 37 | 35 | 33 | 31 | 29 | 27 | 25 | 24 106 | 38 | 36 | 34 | 32 | 30 | 28 | 27 | 25 108 | 39 | 37 | 35 | 33 | 31 | 29 | 28 | 26 | | | | | | | | 110 | 40 | 38 | 36 | 34 | 32 | 30 | 29 | 27 112 | 41 | 39 | 37 | 35 | 33 | 31 | 30 | 28 114 | 41 | 40 | 38 | 36 | 34 | 32 | 31 | 29 116 | 42 | 40 | 38 | 37 | 35 | 33 | 31 | 30 118 | 43 | 41 | 39 | 37 | 36 | 34 | 32 | 31 | | | | | | | | 120 | 44 | 42 | 40 | 38 | 38 | 35 | 33 | 31 122 | 44 | 42 | 41 | 39 | 37 | 36 | 34 | 32 124 | 45 | 43 | 41 | 40 | 38 | 36 | 35 | 33 126 | 46 | 44 | 42 | 40 | 39 | 37 | 35 | 34 128 | 46 | 44 | 43 | 41 | 39 | 38 | 36 | 34 | | | | | | | | 130 | 47 | 45 | 43 | 42 | 40 | 38 | 37 | 35 132 | 47 | 46 | 44 | 42 | 41 | 39 | 37 | 36 134 | 48 | 46 | 44 | 43 | 41 | 40 | 38 | 36 136 | 48 | 47 | 45 | 43 | 42 | 40 | 39 | 37 138 | 49 | 47 | 45 | 44 | 42 | 41 | 39 | 38 | | | | | | | | 140 | 49 | 48 | 46 | 44 | 43 | 41 | 40 | 38 ------------+----+----+----+----+----+----+----+----

A relative humidity of between sixty-five and seventy per cent. should be maintained in all living and sleeping rooms, if one is to escape colds, catarrh, and possibly pneumonia. Some nervous disorders are aggravated if not actually caused by the dryness of the air in steam and other heated apartments during the time that the windows are closed in cold weather. The vanity of the female sex is appealed to with the statement that nothing is more essential to securing and preserving a good complexion than the maintaining of a proper humidity in one’s own room. Efficient and simple and inexpensive humidifiers are now coming on the market. They are almost as necessary to the health of a household as stoves and furnaces. Often a right degree of moisture can be created by leaving clean water in the bathtub and in all wash basins and sinks. One may be surprised on taking humidity observations to find how quickly it increases in rooms two or three removed from the bathroom after water is run into the tub, and especially if the shower spray is turned on and allowed to operate for a few minutes.

In cold weather we maintain the aridity of the Sahara Desert in our hot, steam-heated apartments, with a relative humidity of less than thirty per cent. Is it any wonder that when we step from this atmosphere into the cold outside air, with a humidity of seventy per cent., the violent change is productive of harm, particularly to the delicate mucous membranes of the upper air passages, which have been irritated and their powers of resistance weakened by the dryness within? The period of pneumonia is the season of artificial heat in living rooms—or, more properly speaking, the period of indoor desert aridity.

=Save Fuel by Moistening Air.= If a room at 68° is not warm enough for any healthy person it is because the humidity is too low, and water should be evaporated to bring the moisture up to sixty-five or seventy per cent. of saturation. Water instead of coal should be used to make rooms comfortable when the temperature has reached 68°. Ten to fifteen per cent. of fuel could be saved in the heating of places of habitation if the air were properly and healthfully humidified. The reason for this is that if the air is dry the heat passes through it and warms it but little. Moisture stops the radiated heat that would be lost, absorbs it, and holds it at the place where it is needed. It has precisely the same effect as a soft wool blanket wrapped about the body of each person. The dry air permits such a rapid evaporation from the human body that one may actually feel colder with a dry air heated to 75° than in a moist air at 66° or 68°. Water is cheaper than coal, and in this matter much more healthful.

The cooling effect produced by a draught does not necessarily arise from the wind being cooler, for it may be actually warmer, but arises from the rapid evaporation it causes on the surface of the skin. Vapor of water forms a blanket about the earth and prevents it from scorching during the day and freezing during the night.

=How to Forecast Weather with Only an Aneroid Barometer.= No one except an expert observer should use the mercurial barometer. The aneroid will answer as well for the purpose of forecasting from a single instrument; it is cheaper and less complicated. First learn your elevation above sea level; then add to the observed reading of your instrument .10 for each one hundred feet elevation. Note the fall or rise and the direction of the wind and with the aid of the table on page 76 highly satisfactory forecasts may be made by any intelligent person. Skill will come with practice. Write down your forecasts each day as you make them and the following day note in a blank space left for the purpose the success or failure of your effort. Thus will you profit by your mistakes.

As a rule winds from the east quadrants and falling barometer indicate foul weather, and winds shifting to the west quadrants indicate clearing and fair weather. The rapidity of the storm’s approach and its severity are indicated by the rate and the amount in the fall of the barometer. This applies to the Mississippi Valley and eastward to the Atlantic Ocean. Conditions are different in the Rocky Mountains, on the plateau of the mountains, and on the eastern Rocky Mountain slope, where precipitation seldom begins until after the barometer begins to rise after a fall, and the winds have shifted to the northwest.

Keep in mind that storms are great atmospheric eddies drifting from the west, with the winds blowing cyclonically toward the center; that when your wind is northeast the center of the storm is southwest of you; that when it is east the center is west; when it is south the center is north; when it is southwest the center is northeast, and when it is west or northwest the center is east of you.

=Difference between Weight and Pressure of the Air.= Air at sea level and at 32° temperature weighs one and one third ounces per cubic foot. A room twenty by twenty by ten feet contains some 333 pounds of air. The pressure of the air is a quite different thing. It is the sum of the weights of all the cubic feet of air that are stacked up, one on top of the other, clear to the top of the atmosphere. This is why the higher one goes, the less the pressure of the air, because there are a less number of cubic feet above. And then each cubic foot weighs a slight fraction less than the one just beneath it because the air has expanded. The room afore-mentioned sustains a pressure of 5880 on its floor and a like pressure on its ceiling, and a half of this pressure on each of the sides of the room. The room does not collapse because the air exerts a like pressure on the outside of the room and the two pressures are equal—one inward and the other outward.

[Illustration: FIG. 7.—Mercurial Barometer. The glass tube on right is filled with mercury. With the thumb over the open end, it is reversed so that its open end rests under the surface in a basin of mercury on the left, and the mercury in the tube falls to _n_, at which point it is sustained by pressure of the air on surface of the mercury in the basin.]

=The Principle of the Barometer.= In 1643 some Florentine gardeners found that they could pump water only thirty-three feet high. This is because the entire volume of air, if it were compressed to the density of water, would equal a covering around the earth of that depth. When the gardeners first began to work the plungers in their pump up and down they did not get water; it was necessary for them first to pump out all the air in the pipe leading down to the water in the well; then the water rose into the vacuum thus created, and it rose to a height that just balanced the weight or pressure of the whole body of air that rests upon the earth. Now, if the atmosphere surrounding the earth could be reduced to the density of mercury it would equal a covering only thirty inches deep; this is why the mercury normally stands at thirty inches high in the vertical vacuum tube of the barometer. (Figure 7.) In the complete barometer a graduated scale is attached so as to measure the fluctuations in the height of the mercury. If one were to ascend in a balloon it would be found that the mercury would steadily fall with increasing altitude, until at eighteen thousand feet one half of the atmosphere would be left below and the instrument would read only fifteen inches instead of thirty. In ascending to the top of the Washington Monument, 555 feet, the pressure of the air decreases over one half inch.

The barometer rises and falls with the passage of storms because wind movement displaces air and causes it to accumulate at some places and become deficient at others, but in order to compare barometers exposed at many different elevations with the view of determining the geographic position of storm centers—of cyclones and anti-cyclones—it is necessary to reduce all barometric readings to sea level.

=Weather Records Turn the Scales of Justice.= How trivial the incident that may change the whole course of a lifetime and lead to peace and happiness or to discord and sorrow! Likewise the parting of the clouds and the coming through of the sunshine, or the moment of the beginning of rainfall, or the amount of rain that falls within a given time, or the direction of the wind, or the velocity of the wind, or the temperature of the air, or the depth of the snowfall literally thousands of times has furnished the evidence in courts of law that has turned the scales of justice in civil suits involving large sums of money, and in criminal cases where a prison sentence or the hangman’s noose threatened the defendant.

For illustration let us say that a ship breaks from its mooring, crashes into another ship in the harbor and sinks it. If the force of the storm is no greater than has previously occurred in that harbor, the first ship is liable for the loss of the second ship. But if the automatically recording instruments of the Weather Bureau show that at that time the velocity of the wind was greater than ever had been known before, then the loss is due to “an act of God” and the ship that broke her mooring is not liable for damages to the ship that was sunk, provided proper provision was made for such velocity of wind as reasonably might be expected to occur with the passage of a storm.

To cite a case that actually occurred: A railroad company was sued for the loss of a million dollars’ worth of lumber that was burned, as alleged, by sparks from one of its locomotives. Here came in the wind records of the Government and proved that at the time of the starting of the fire the wind was steadily and forcefully blowing in a direction opposite to what would carry the sparks to the lumber, and the company was protected against an unjust verdict.

Again heavy rain fell in excess of the capacity of the sewers of a city to carry away the water, and private property was damaged by the flood. In this case the city was compelled to pay for the damage to property, because the records of the Weather Bureau showed that previous rainfalls had been of equal or greater amount in the same period of time, and the city should have constructed its sewers of sufficient capacity to carry away such precipitation as experience showed was liable to occur.

The writer was once an expert witness in what then was a famous case. The defendant, a young and handsome woman previously of unimpeachable character, was being sued for divorce. Two witnesses swore that they had seen her come to an open window, facing south, at seven o’clock in the morning, in a house in which she should not have been, stand for several minutes looking into the garden upon which the window faced, clad only in her night robe. Unfortunately the woman was not able to establish a satisfactory alibi for the morning in question, and she stood facing a terrible calamity with no power to establish her innocence. Her accusers had given as a reason why she stood so long at the open window that the morning was warm and balmy. But, fortunately for the innocent woman, the weather records came to her defense when her case seemed hopeless and her life was about to be blighted with a scandal from which she never would be able to free herself, and proved that at the very time when she was supposed to have been standing in the open window a torrential rain was falling and a wind of fifty miles per hour was beating upon the outside of the window panes. The woman was acquitted and one of the witnesses spent several hundred balmy mornings behind prison bars.

At another time the writer came into a case where a robber had shot and killed a citizen who surprised him in the committing of his crime. The robber was on trial for murder and his lawyers were attempting to clear him by the introduction of evidence to prove that the day was so foggy that the State’s witnesses had blundered and seized the wrong man when they chased the murderer around a corner. The weather expert destroyed the only evidence that tended to raise a doubt in the mind of the jury as to the man’s guilt, by testifying that fog could come to the surface of the earth only when the air was abnormally light and the wind calm or only gentle; while at the time of the murder the barometer was unusually high and the wind brisk. Here again the meteorological records aided in vindicating the right, and secured the conviction and execution of a brutal murderer.

A remarkable case was that in which a tramp was being tried for the murder of a miserly old woman who was believed to carry a large amount of money about her person. The tramp came to her door and asked for food. She took him in and fed him and soon thereafter he was seen hastily to leave the house. An hour after he had gone the woman was found murdered and her clothing rifled. The tramp was overtaken, found to have a large amount of money of small denominations in his pockets, indicted, and placed on trial. The principal witness for the State was a man who was repairing a frozen water pipe in a trench by the side of the house opposite to that by which the tramp entered and left. He saw the blow struck, ran in fear to his home, and then informed the police. In explaining how he came to see the criminal act, he testified that he climbed out of the trench to get a drink from a bucket standing near by, and as he raised the bucket his eye came in line with a window of the house, through which he witnessed the murder. The case seemed clear against the tramp, as other witnesses had seen him enter and leave the house and positively recognized him. Just here his lawyer asked the trench digger how long the water bucket had been sitting by the side of the trench. The latter said it had been there from 7 o’clock until 10. Then the weather records came in to confound the falsifier and to vindicate innocence, for the automatic tracing of the pen that records every movement of the temperature proved that the temperature had not been above zero any time during the three hours that the bucket had been exposed and that it contained a solid chunk of ice if it contained anything. The trench digger then confessed that he himself was the murderer. He had seen the tramp enter and leave and thought it a favorable opportunity to commit the crime and put the evidence on another.