Influence Of The Moon
( Originally Published 1851 )
A late number of the Foreign Quarterly Review contains a notice of some scientific inquiries, made by a French gentleman, M. Arago, into the influence of the moon. The first question, which M. Arago undertakes to examine, is, whether the moon exercises any influence on the rain; and the result of his investigations is, that, if' certain observations may be relied upon, it rains more frequently during the increase than during the wane of the moon.
The influence of the moon on the terrestrial atmosphere seems also to be rendered evident by observations of a different kind, namely, the mean heights of the barometer at the different lunar phases. The conclusion of' i 1. Arago is, however, that " the inequalities of pressure indicated by observation must be referred to some cause different from attraction; to some cause certainly depending on the moon, but of which the nature and mode of action still remain to be discovered."
Among the ancients the opinion was universally entertained that the different aspects of the moon furnish sure prognostics of the future state of the weather.
"If," says Aratus, " on the third day of the moon the horns of the crescent are sharp and well defined, the sky will continue serene during the whole of the month."
This is a notion which we believe to be very prevalent at the present day among the farmers of our own country. The following is the commentary of Arago.
In reality, when the moon in the evening begins to disengage herself from the sun's rays, she has always the form of a crescent, terminated by two very sharp horns; but if the atmosphere happens to be troubled, the horns appear enlarged. This enlargement, however, is a mere optical illusion, and is occasioned by strongly illuminated clouds, in apparent contact with the moon, and seeming to form a constituent part of her body. The fine extremities of the crescent are then lost as it were in the parasitical light which surrounds the moon, and become invisible to the naked eye. All this is rendered evident by employing a telescope, which destroys the illusion."
Many other aphorisms of the same nature might be quoted from Aratus, 'neon, Theophratus, Pliny, and other ancient writers on rural affairs. But they may be dismissed with the general remark that they had their origin in that ignorance which con-founds signs with causes, and are now disregarded, excepting by the most illiterate and credulous. They are besides at total variance with the theory of the influence of the phases.
It is generally believed, especially in the neighborhood of Paris, that the moon, in certain months, has a great influence on the phenomena of vegetation. The gardeners give the name of red moon (lune rousse) to the moon which, beginning in April, becomes full either about the end of that month, or more usually in the course of May. In the months of April and May the moon, according to them, exercises a pernicious influence on the young shoots of plants. They maintain that they have observed during the night, when the sky is clear, the leaves and buds exposed to this light to become red, that is to say, to be frozen, although the thermometer, in the free atmosphere, stood several degrees above the freezing point. They also assert, that if the rays of the moon are intercepted by clouds, and thereby prevented from reaching the plants, the same effects do not take place, under circumstances perfectly similar in other respects with regard to temperature.
Now it has been proved by Dr. Wells, that terrestrial substances, excepting in the case of a very rapid evaporation, may acquire during the night, a different temperature from that of the surrounding air. On placing little masses of cotton, down, &c. in the open air, it is frequently observed they acquire a temperature of six, seven, or even eight centigrade degrees below that of the surrounding atmosphere. The same is the case with vegetables. We cannot therefore judge of the degree of cold with which a plant is affected during the night by the indications of a thermometer suspended in the free atmosphere: the plant may be strongly frozen, although the air remains constantly several degrees above the freezing point. These differences of temperature between solid bodies and the atmosphere only rise to six, seven or eight degrees of the thermometer, when the sky is perfectly clear. If the sky is clouded, they become insensible.
" It is now necessary to point out the connexion between these phenomena and the opinions of the country people regarding the April moon.
" In the nights of April and May the temperature of the atmosphere is frequently only 4, 5, or 6 centigrade degrees above zero. When this happens, plants exposed to the moon, that is to say, to a clear sky, may be frozen, notwithstanding the , indications of the thermometer. If the moon, on the contrary, does not shine in short, if the sky is cloudy, the temperature of the plants does not fall below that of the atmosphere, and they will consequently not be frozen unless the thermometer indicates zero. It is therefore quite, true, as the gardeners pretend, that under thermometrical circumstances precisely alike, a plant may be frozen or not, according as the moon may he visible or concealed behind clouds. If they are deceived, it is only in their conclusion, in attributing the effect to the light of the moon. The moon's light is, in this case, only the index of a clear atmosphere; it is only in consequence of the clearness of the sky, that the nocturnal congelation of plants takes place; the moon contributes to the effect in no way what-ever; although she were hid under the horizon the effect would not be different."
The explanation here given is perfectly satisfactory, and may be extended to some other notions that have prevailed respecting the lunar influence. For example, it is said by Pliny and Plutarch, and is at the present day generally believed in the %Vest Indies that the moon sheds a copious humidity on bodies exposed to her rays, and that her light hastens the putrefaction of animal substances. This opinion is, to a certain extent, countenanced by facts.
" A body exposed to the light of the moon, that is to say, to a clear sky, becomes, in consequence of its radiation, colder than the surrounding air. Under these circumstances the air deposits a portion of its humidity on the cold surface of the body, which is neither more nor less than the phenomenon of dew, as analyzed by Doctor Wells.-Now, animal substances become much sooner putrid when moist than when dry. The observation of Pliny and Plutarch is therefore correct in all its details. It was only necessary to reform the theory, and acquit the moon of the mischief ascribed to her."
We must close our extracts by quoting from the American Fanner the following remarks in reference to this subject:—" As it respects the influence of the moon on the weather, on crops, &c. we have no doubt that the general belief in it has due as much harm to the agricultural interest, as any other evil with which fanners and planters have to contend. How often do farmers omit a favorable season to plant a crop of potatoes, &c. because it is 'not the right time of the moon.' Many people will not kill hogs or beef, unless at a particular time of the moon. And when the ' right time of the moon' does come, it is at least an equal chance that the state of the weather will not admit of these operations, or some other more necessary business must be performed, and of course they must be put off till the moon comes round again to the proper ' time.' Almost every body can tell what weather we are to have for the next four weeks, by looking at the new moon, and lay out their work accordingly. If the horns of the new moon are perpendicular, they say we are to have a wet moon, and at haying and harvest time, many a good crop is saved by the prompt advantage taken of every clear day; because, they say, we shall have very few such days this moon. This, to be sure, is a very useful error; but its opposite more than balances the account. When the new moon shows her horns in a horizontal position, somewhat like a section of a bowl slightly inclined upon its side, then they say we shall have a dry moon, and the hay and the crops are neglected, because ' we shall have plenty of dry weather this moon.' Now there is no ' old saw' more useful to farmers, than the good old adage—' make hay while the sun shines;' which means, do whatever you have to rio, and can do, TODAY, and let the moon mind her own business, as you may be sure she is inclined to, if you will only let her alone she cares no more for your potatoes and pork, and exercises no more influence over your operations ' than the man in the moon.'