The Antipodes - Morning and Evening Dew by Albany Poyntz

It is a gratifying thing when popular prejudices are overcome by the progress of public enlightenment. The existence of the antipodes was formerly disbelieved. Before the spherical form of our globe was ascertained, how was it possible to suppose that there existed human beings under our feet standing with their head downwards?

Till the Newtonian theory was developed, it seemed impossible but that persons so placed must fall into the realms of endless space. There is a general disposition in human nature to believe all that is impossible as well as to doubt every thing that really exists; and such was the incredulity of the world with regard to the antipodes.

The ancients, who admitted many absurdities, denied the existence of the antipodes. The Fathers of the Church followed in their steps; some indeed pronounced it heresy to hold such a belief. St. Augustin expressly says, “Take heed lest thou believe such a fable.” In his treatise on the Acts of the Apostles, there is an argument remarkable enough, considering that the rotundity of the earth was then unknown. “Faith teaches us, that all men are from Adam. But if there were other men under the earth, they could not be of Adam. How could they have found their way to the antipodes? Not by land, for the antipodes are cut off from our hemisphere by boundless seas. Not by sea; for the most experienced pilot would not dare launch his vessel in such boundless space. It is, therefore, evident that the doctrine of the antipodes is false and heretical.” Time and experience have taught us the folly of deciding upon topics exceeding our comprehension. Yet, perhaps, even now we deny a host of truths, which at some time may give us an insight into futurity. In great as well as trifling things, every day brings its tribute to the cause of truth. The antipodes are admitted to exist. The earth revolves round the sun, though once supposed to be stationary in its place in the heavens; while the dew, which our ancestors believed to descend from heaven, is known to be an emanation from the earth.”

Such an error was pardonable enough. The dews are often made use of in Holy Writ as a term of comparison; and the mercy of the Lord is implored to descend upon his people like the dews from heaven. After many experiments in elucidation of the origin of dew, a scientific observer obtained the following results.

Having placed some plants under glass bells, he examined them the following morning, and finding them to be covered with dew like those left in the air, he cut shreds of flannel; and placing them at graduated heights, found that those nearest the earth were first wet, and that the dew gradually rose towards the highest. Upon weighing the shreds, he found those below to be the most saturated. Lastly, upon examining plants grown in green-houses, he felt convinced that they also imbibed abundant dew. These experiments excited attention; and Muschembroek, the author, had many imitators. Among others, Dufay, who placed a double ladder thirty-two feet high, in the centre of a garden, suspending tablets of glass at different altitudes; so that each was equally exposed to the action of the atmosphere. He remained at the foot of the ladder to watch the progress of the phenomenon, and found that the tablets nearest the earth were the first moist, and that the humidity ascended gradually to the highest. Several other men of science repeated the same experiment with similar results.

The problem was thus solved, and proof obtained that dew ascended from the earth. To the joy, however, of some, a doubt presented itself. By renewed experiments it was found that this dew from the earth did not equally affect all bodies, and was partial in its bearing. For instance, it appeared to avoid gold, silver, metal, and polished marbles; while it adhered to glass, oily and resinous substances.

Place a gold or plated vessel under a crystal vase in a garden during the night, and in the morning you will find the edges perfectly dry, while the crystal vase will be wet. The cause of this difference is not accounted for. Reaumur supposes, but does not affirm, that the golden vessel, containing more caloric than the crystal, repels the dew, while the latter attracts it.

In confirmation of this supposition, Reaumur proposed the following experiment. Place a china cup upon a stone within a hot-bed; and further on, and beyond the influence of the hot-bed, another cup of similar form, substance, and diameter; this will be charged with dew, the other will remain dry. In explanation of this difference, it may be imagined that the phenomenon of which they sought the solution, originated in electricity; an opinion, however, which has no influence over the main discovery that dews arise from the ground, instead of falling from the skies, as asserted by the mythology of the ancients, and the tropes of Scripture.