IT is more than three centuries and a half since Fernando de Magulhane observed that the moon, during a solar eclipse, was not perfectly opaque. He says:--
"On the forenoon of October 11th, 1520, an eclipse of the sun was expected. At eight seconds past ten a.m. the sun, having then reached the altitude of 42°, began to lose its brightness, and gradually continued so to do, changing to a dark red colour, without any cloud intervening that could be perceived. No part of the body of the sun was hid, but the whole appeared as when seen through a thick smoke, till it passed the altitude of 44½°, after which it recovered its former lustre." 1
During a partial solar eclipse the sun's outline has many times been seen through the body of the moon. But those who have been taught to believe that the moon is a solid opaque sphere, are ever ready with "explanations," often of the most inconsistent character, rather than acknowledge the simple fact of semi-transparency. Not only has this been proved by the visibility of the sun's outline through segments, and sometimes the very centre, of the moon, but often, at new moon, the outline of the whole, and even the several shades of light on the opposite and illuminated part have been distinctly seen. In other words we are often able to see through the dark side of the moon's body the light on the other side.
"In this faint light the telescope can distinguish both the larger spots, and also bright shining points, and even when more than half the moon's disc is illuminated, a faint grey
light can still be seen on the remaining portion by the aid of the telescope. These phenomena are particularly striking when viewed from the high mountain plateaus of Quito and Mexico." 1
Many have laboured hard to make it appear that these phenomena are the result of what they have assumed to be light reflected from the earth--"Earth light," "the reflection of a reflection." The sun's light thrown back from the moon to the earth and returned from the earth to the moon! It seems never to have occurred to these "students of imagination" that this so-called "earth-light" is most intense when the moon is youngest, and therefore illuminates the earth the least. When the operating cause is least intense, the effect is much the greatest!
Besides the fact that when the moon is only a few hours old, and sometimes until past the first quarter, the naked eye is able to see through her body to the light shining on the other side, both fixed stars and planets have been seen through a considerable part of her substance, as proved by the following quotations
"On the 15th of March, 1848, when the moon was seven and a half days old, I never saw her unillumined disc so beautifully. . . . On my first looking into the telescope a star of about the 7th magnitude was some minutes of a degree distant from the moon's dark limb. I saw that its occultation by the moon was inevitable. . . . The star, instead of disappearing the moment the moon's edge came in contact with it, apparently glided on the moon's dark face, as if it had been seen through a transparent moon; or, as if a star were between me and the moon. . . .
[paragraph continues] I have seen a similar apparent projection several times. . . . The cause of this phenomenon is involved in impenetrable mystery." 1
"Occultation of Jupiter by the moon, on the 24th of May, 1860, by Thomas Gaunt, Esq. 'I send you the following account as seen by me at Stoke Newington. The observation was made with an achromatic of 3.3 inches aperture, 50 inches focus; the immersion with a power of 50, and the emersion with a power of 70. At the immersion I could not see the dark limb of the moon until the planet appeared to touch it, and then only to the extent of the diameter of the planet; but what I was most struck with was the appearance on the moon as it passed over the planet. It appeared as though the planet was a dark object, and glided on to the moon instead of behind it; and the appearance continued until the planet was hid, when I suddenly lost the dark limb of the moon altogether.'" 2
"Occultation of Jupiter by the moon, May 24, 1860, observed by T. W. Burr, Esq., at Highbury. The planet's first limb disappeared at 8h. 44m. 6.7s., the second limb disappeared at 8h. 45m. 4.9s. local sidereal time, on the moon's dark limb. The planet's first limb reappeared at 9h. 55m. 48s.; the second limb reappeared at 9h. 56m. 44.7s., at the bright limb. The planet was well seen, notwithstanding the strong sunlight (4h. 34m. Greenwich mean time), but of course without any belts. The moon's dark limb could not be detected until it touched the planet, when it was seen very sharply defined and black; and as it passed the disc of Jupiter in front appeared to brighten. So that the moon's limb was preceded by a bright band of light, doubtless an effect of contrast." 3
"Occultation of the Pleiades, December 8, 1859, observed at the Royal Observatory, Greenwich; communicated by the Astronomer Royal. Observed by Mr. Dunkin with the alt-azimuth, the disappearance of 27 Tauri was a most singular phenomenon; the star appeared to move a considerable time along the moon's limb, and disappeared behind a prominence at the first time noted (5h. 34m.); in a few seconds it re-appeared, and finally disappeared at the second time noted (5h. 35m.)."
"Observed by Mr. Criswich, with the north equatorial, 27 Tauri was not occulted at all, though it passed so close to some of the illuminated peaks of the dark limb as hardly to be distinguished from them." 1
In the "Philosophical Transactions" for 1794 it is stated:--
Three persons in Norwich, and one in London, saw a star on the evening of March 7th, 1794, in the dark part of the moon, which had not then attained the first quadrature; and from the representations which are given the star must have appeared very far advanced upon the disc. On the same evening there was an occultation of Aldebaran, which Dr. Maskelyne thought a singular coincidence, but which would now be acknowledged as the cause of the phenomenon." 2
The above quotations are only a few from many cases which have been recorded; and if, with the evidence advanced in the chapter on eclipses, they are insufficient to prove that the moon is not an opaque reflecting body but is really a semi-transparent, self-luminous structure, to such minds evidence is valueless, and reasoning a
vain pretension. Nothing could possibly for a moment prevent such a conclusion being at once admitted, except the pre-occupation of the mind by a strabismic presumptuous hypothesis, which compels its votaries to yield assent to its details, even if directly contrary to every fact in the natural world, and to every principle of mental investigation.
337:1 "Discoveries in the South Sea," p. 39, by Captain James Burney.
338:1 "Description of the Heavens," p. 354, by Alex. von Humboldt.
339:1 Sir James South, of the Royal Observatory, Kensington, in a letter in the "Times" newspaper of April 7, 1848.
339:2 Monthly Notices of Royal Astronomical Society, for June 8, 1860.
339:3 Monthly Notices of Royal Astronomical Society for June 8, 1860.
340:1 Monthly Notices of Royal Astronomical Society, December 9, 1859.
340:2 Rev. T. W. Webb in Monthly Notice of Royal Astronomical Society for May 11, 1860.