OZONE.
The atmosphere, besides holding the vapour of water diffused throughout its mass, contains also minute traces of carbonic acid and ammonia, and a very remarkable substance called Ozone. Oxygen, one of the component gases of the atmosphere, is capable of existing in two conditions; one in which it is comparatively passive, and another in which it possesses exceptional chemical activity, dependent apparently upon its electrical condition, and in which state it possesses a peculiar smell which has caused it to be named ozone.[[16]] The characteristic odour is always observable near a powerful electric machine when it is being worked, near a battery used for the decomposition of water, and in the air after the passage of a flash of lightning. Its presence is most marked near the sea-coast, and in localities remarkable for their salubrity; and on account of its influence on health, it has been proposed by Schonbein and others to include ozonometrical observations with the ordinary meteorological observations.
[16]. Greek ozo, I smell.
Although in minute quantities it is favourable to health, when existing in undue proportion it irritates the mucous membrane of the nose and throat, producing painful sores. It attacks india-rubber, bleaches indigo, and oxidizes silver and mercury, differing in all these points from ordinary atmospheric oxygen.
The chemical energy it possesses (which exceeds that of ordinary oxygen as much as the latter exceeds atmospheric air as an oxidizing agent) affords the means of ascertaining its presence and quantity. It liberates iodine from its combination with potassium, and free iodine colours starch a deep blue.
Schonbein, the discoverer of ozone, found that when strips of paper previously saturated with starch and iodide of potassium and dried were exposed freely to the air but protected from rain and the direct action of the sun, they underwent a peculiar discoloration (when immersed in water) after an exposure of 24 hours. A scale of tints numbered from one to ten afforded the means of comparative observation, and thus the Ozonometer was constructed, and a means established of registering the amount of ozone in the air of various localities from day to day.
Schonbein also observed that the proportion of ozone was largely augmented after heavy falls of snow. For the exposure of the ozone papers, an ozone cage is employed, as shown at Fig. 67.
67.
Ozone Cage.
Scale about 1/6.
Ozone may be prepared artificially as a disinfectant by cautiously mixing without friction or concussion equal parts of peroxide of manganese, permanganate of potash, and oxalic acid. For a room containing 1,000 cubic feet, two teaspoonfuls of the powder, placed in a dish and moistened with water occasionally, will develop the ozone and disinfect the surrounding air without producing cough.
The most important and interesting series of facts, however, connected with ozone are those established by the researches of M. Houzeau, who states:—
1. That country air contains an odorous oxidizing substance, with the power of bleaching blue litmus, without previously reddening it, of destroying bad smells, and of bluing iodized red litmus.
2. That this substance is ozone.
3. That the amount of ozone in the air at different times and places is variable, but this is at most 1/700,000 of its volume, or 1 volume of ozone in 700,000 of air.
4. That ozone is found much more frequently in the country than in towns.
5. That ozone is in greatest quantity in spring, less in summer, diminishes in autumn, and is least in winter.
6. It is most frequently detected on rainy days, and during great atmospheric disturbances.
7. That atmospheric electricity is apparently the great generator of ozone.
The subject is one of great interest in its bearings on health, and opens a wide field of scientific research, as may be inferred from the opinion expressed by the Vienna Congress, which is that “the existing methods of determining the amount of ozone in the atmosphere are insufficient, and the Congress therefore recommends investigations for the discovery of better methods.”
Mr. Lowe has published the valuable weather warnings tabulated on page [94], which are interesting as showing from a given number of observations the value of each phenomenon:—
| No. of observations. | Followed in 24 hours by | ||
| DEW. | Fine. | Rain. | |
| Dew profuse | 241 | 196 | 43 |
| Dew from 1st April to 30th Sept. | 185 | 161 | 24 |
| Dew from 1st Oct. to 30th March | 56 | 37 | 19 |
| CLOUDS. | |||
| White stratus in the valley | 229 | 201 | 28 |
| Coloured clouds at sunset | 35 | 26 | 9 |
| SUN. | |||
| Solar halos | 204 | 133 | 71 |
| Sun red and shorn of rays | 34 | 31 | 3 |
| Mock suns | 35 | 19 | 6 |
| Sun shone through thin cirro-stratus | 13 | 6 | 7 |
| Sun pale and sparkling | 51 | 27 | 24 |
| FROST. | |||
| White frost | 73 | 59 | 14 |
| MOON. | |||
| Lunar halos | 102 | 51 | 51 |
| Mock moons | 9 | 7 | 2 |
| Lunar burr | 64 | 47 | 17 |
| Moon shining dimly | 18 | 12 | 6 |
| Moon rose of a red colour | 8 | 7 | 1 |
| STARS. | |||
| Falling stars abundant | 85 | 65 | 20 |
| Stars bright | 83 | 64 | 19 |
| Stars dim | 54 | 32 | 22 |
| Stars scintillated | 14 | 12 | 2 |
| AURORA. | |||
| Aurora borealis | 76 | 49 | 27 |
| ANIMALS. | |||
| Bats flying about in the evening | 61 | 45 | 16 |
| Toads in the evening | 17 | 12 | 5 |
| Landrails clamorous | 14 | 13 | 1 |
| Ducks and geese noisy | 10 | 7 | 3 |
| Spiders hanging on webs in the evening | 8 | 5 | 3 |
| Fish rise in the lake | 15 | 9 | 6 |
| SMOKE. | |||
| Smoke rising perpendicularly | 6 | 5 | 1 |
Among the animals whose movements give weather warnings few are more trustworthy than the leech. The reader may verify this by placing one in a broad glass bottle, tied over with perforated leather, or bladder. If placed in a northern aspect, the leech will be found to behave in the following manner:—
1. On the approach of fine or frosty weather, according to the season, it will be found curled up at the bottom. 2. On the approach of rain, snow, or wind, it will rise excitedly to the surface. 3. Thunder will cause it to be much agitated, and to leave the water entirely.
Periods.—M. Köppen states, as the result of his examination into the chances of a change of weather, that the weather has a decided tendency to preserve its character. Thus, at Brussels, if it has rained for nine or ten days successively, the next day will be wet also in four cases out of five; and the chance of a change decreases with the length of time for which the weather from which the change is to take place has lasted.
In the case of temperature for five-day periods, the same principle holds good;[[17]] for if a cold five-day period sets in after warm weather, we can bet two to one that the next such period will be cold too; but if the cold has lasted for two months, we can bet nearly eight to one that the first five days of the next month will be cold too. The chance of change is, however, greater for the five-day periods than for single days. Similar results follow for the months, but here again the chance of change shows an increase.
[17]. “Recent Progress in Weather Knowledge,” by R. H. Scott, F.R.S.
“If we revert to the instance first cited, that of rain, the result is, not that if it once begins to rain the chances are in favour of its never ceasing; all that is implied is, that the chances are against its ceasing on a definite day, and that they increase with the length of time the rain has lasted. The problem is similar to that of human life: the chance of a baby one year old living another year is less than that of a man of thirty.
“The practical meaning of all this is, that although we know that a compensating anomaly for all extraordinary weather exists somewhere on the earth’s surface, e.g., the very common case of intense cold in America, while we have a mild winter in Britain, there is no reason as yet ascertained to anticipate that this compensation will occur at any given place during the year. In other words, when definite conditions of weather have thoroughly established themselves, it is only with great difficulty that the courses of the atmospheric currents are changed.”
To bring within the limits of a popular pamphlet a notice of the various phenomena classed under the head of Meteorology, it has been necessary to exercise the utmost brevity. Brief, however, as the treatment has been, reference has been made to the sciences of Heat, Light, Electricity, Magnetism, Gravitation, Astronomy, Chemistry, Geography, and Geology, thus corroborating the testimony of Sir John Herschel, who states that “it can hardly be impressed forcibly enough on the attention of the student of nature that there is scarcely any natural phenomenon which can be fully and completely explained in all its circumstances without a union of several—perhaps of all—the sciences; and it cannot be doubted that whatever walk of science he may determine to pursue, impossible as it is for a finite capacity to explore all with any chance of success, he will find it illuminated in proportion to the light which he is enabled to throw upon it from surrounding regions. But, independently of this advantage, the glimpse which may thus be obtained of the harmony of Creation, of the unity of its plan, of the theory of the material universe, is one of the most exalted objects of contemplation which can be presented to the faculties of a rational being. In such a general survey he perceives that science is a whole whose source is lost in infinity, and which nothing but the imperfection of our nature obliges us to divide. He feels his nothingness in his attempts to grasp it, and he bows with humility and adoration before that Supreme Intelligence who alone can comprehend it, and who ‘in the beginning saw everything that He had made, and behold it was very good.’”
J. AND W. RIDER, PRINTERS, LONDON.
Transcriber’s note:
Footnotes moved to end of paragraph.
All scale values in illustration captions retained. The value may not be visually correct.
All fractions regularised to numerator/denominator.
Page 3, ‘Reaumur’s’ changed to ‘Réaumur’s,’ “Réaumur’s scale”
Page 9, closing single quote changed to double quote.
Page 12, full stop appended to illustration caption, “Scale about 1/20.”
Page 16, full stop appended to illustration caption, “9.”
Page 17, semicolon changed to full stop, “...it has never been frozen.”
Page 23, first footnote changed from “8 R = 18 F.” to “8 R = 50 F.”
Page 27, ‘vice versâ’ changed to ‘vice versa,’ “...proportion, and vice versa,...”
Page 30, dash changed to space, “29·500 inches.”
Page 34, ‘Hook’ changed to ‘Hooke,’ “...invented by Dr. Hooke.”
Page 37, ‘Aneriod’ changed to ‘Aneroid,’ “...by means of Barometer or Aneroid,...”
Page 39, space changed to stop, “...between nine and ten p.m.”
Page 42, space inserted between ‘no’ and ‘less,’ “...at no less than 212 miles.”
Page 46, illustration number added to caption, “38. Damp Detector.”
Page 51, comma moved to after ‘weather,’ “In cold calm weather,...”
Page 57, ‘!’ changed to ‘,’ “cloud reflector,”
Page 58, ‘2.’ changed to ‘2nd.,’ “...and 2nd. Velocity of Motion.,”
Page 74, degrees changed to minutes, “57° 29´ N.”
Page 79, ‘Guage’ changed to ‘Gauge,’ “Lind’s Anemometer or Wind Gauge...”
Page 83, powers changed from subscripts to superscripts, “V2.”
Page 87, reference in text to Fig. 65 changed to Fig. 64, “...and Fig. 64 an arrangement...”
Page 94, full stops added after ‘STARS’ and ‘ANIMALS.’