An Autobiography [152]
absence of atmosphere. One portion of the moon, on which the sun is shining, is brilliantly illuminated, while all in shade is dark.
While the disc of the sun appears a vast electric light of overpowering rayless brilliancy, every star and planet in the black vault of the lunar heavens is shining with steady brightness at all times; as, whether the Sun be present or absent during the long fourteen days' length of the lunar day or night, no difference on the absolutely black aspect of the lunar heavens can appear. That aspect must be eternal there. No modification* [footnote... a small degree of illumination is, however, given to some portions of the Moon's surface by the Earth-shine, when the earth is in such a position with regard to the Moon, as to reflect some light on to it, as the Moon does to the earth. ...] of the darkness of shadows in the Moon can result from the illuminative effect, as in our case in the earth, from light reflected into shadows by the blue sky of our earthly day The intensity of the contrast between light and shade must thus lend another awful aspect to the scenery of the Moon, while deprived of all those charming effects which artists term "aerial perspective," by which relative distances are rendered cognisable with such tender and exquisite beauty. The absence of atmosphere on the Moon causes the most distant objects to appear as close as the nearest; while the comparatively rapid curvature of the moon, owing to its being a globe only one-fourth the diameter of the earth, must necessarily limit very considerably the range of view.
[Image] Lunar Mountains and Extinct Volcanic Craters
It is the combination of all these circumstances, which we know with absolute certainty must exist in the Moon, that gives to the contemplation of her marvellous surface, as revealed by the aid of powerful telescopes,--one of the grandest and most deeply interesting subjects that can occupy our thoughts; especially when we regard the physical constitution and the peculiar structure of her surface, as that of our nearest planetary neighbour, and also as our serviceable attendant by night.
Then there are the Tides, so useful to man, preserving the sanitary condition of the river mouths and tide-swept shores. We must be grateful for the Moon's existence on that account alone. She is the grand scavenger and practical sanitary commissioner of the earth. Then consider the work she does! She moves hundreds of ships and barges, filled with valuable cargoes, up our tidal rivers, to the commercial cities on their banks. She thus performs a vast amount of daily and nightly mechanical drudgery. She is the most effective of all Tugs; and now that we understand the convertibility and conservation of force, we may be able to use her Tide-producing powers through the agency of electricity for mechanical purposes. It is even possible that the Tides may yet light our streets and houses!* [footnote... It is not quite a century since London was in part supplied with water by the Moon, through employing the tidal action by the waters at Old London Bridge, where the tide mills worked the water-supplying pumps. ...]
Is the moon inhabited? It seems to me that the entire absence of atmosphere and water forbids the supposition--at least of any form of life with which we are acquainted. Add to this adverse condition, the fact of the moon's day being equal to fourteen of our days; the sun shining with much more brilliancy of effect in the moon than on the earth, where atmosphere and moisture act as an important agent in modifying its scorching rays; whilst no such agency exists in the moon. The sun shines there without intermission for fourteen days and nights. During that time the heat must accumulate to almost the melting point of lead; while, on the other hand, the absence of the sun for an equal period must be followed by a period of intense cold, such as we have no experience of, even in the Arctic regions. The highest authorities state that the cold during the Moon's long night must reach as low as 250 degrees
While the disc of the sun appears a vast electric light of overpowering rayless brilliancy, every star and planet in the black vault of the lunar heavens is shining with steady brightness at all times; as, whether the Sun be present or absent during the long fourteen days' length of the lunar day or night, no difference on the absolutely black aspect of the lunar heavens can appear. That aspect must be eternal there. No modification* [footnote... a small degree of illumination is, however, given to some portions of the Moon's surface by the Earth-shine, when the earth is in such a position with regard to the Moon, as to reflect some light on to it, as the Moon does to the earth. ...] of the darkness of shadows in the Moon can result from the illuminative effect, as in our case in the earth, from light reflected into shadows by the blue sky of our earthly day The intensity of the contrast between light and shade must thus lend another awful aspect to the scenery of the Moon, while deprived of all those charming effects which artists term "aerial perspective," by which relative distances are rendered cognisable with such tender and exquisite beauty. The absence of atmosphere on the Moon causes the most distant objects to appear as close as the nearest; while the comparatively rapid curvature of the moon, owing to its being a globe only one-fourth the diameter of the earth, must necessarily limit very considerably the range of view.
[Image] Lunar Mountains and Extinct Volcanic Craters
It is the combination of all these circumstances, which we know with absolute certainty must exist in the Moon, that gives to the contemplation of her marvellous surface, as revealed by the aid of powerful telescopes,--one of the grandest and most deeply interesting subjects that can occupy our thoughts; especially when we regard the physical constitution and the peculiar structure of her surface, as that of our nearest planetary neighbour, and also as our serviceable attendant by night.
Then there are the Tides, so useful to man, preserving the sanitary condition of the river mouths and tide-swept shores. We must be grateful for the Moon's existence on that account alone. She is the grand scavenger and practical sanitary commissioner of the earth. Then consider the work she does! She moves hundreds of ships and barges, filled with valuable cargoes, up our tidal rivers, to the commercial cities on their banks. She thus performs a vast amount of daily and nightly mechanical drudgery. She is the most effective of all Tugs; and now that we understand the convertibility and conservation of force, we may be able to use her Tide-producing powers through the agency of electricity for mechanical purposes. It is even possible that the Tides may yet light our streets and houses!* [footnote... It is not quite a century since London was in part supplied with water by the Moon, through employing the tidal action by the waters at Old London Bridge, where the tide mills worked the water-supplying pumps. ...]
Is the moon inhabited? It seems to me that the entire absence of atmosphere and water forbids the supposition--at least of any form of life with which we are acquainted. Add to this adverse condition, the fact of the moon's day being equal to fourteen of our days; the sun shining with much more brilliancy of effect in the moon than on the earth, where atmosphere and moisture act as an important agent in modifying its scorching rays; whilst no such agency exists in the moon. The sun shines there without intermission for fourteen days and nights. During that time the heat must accumulate to almost the melting point of lead; while, on the other hand, the absence of the sun for an equal period must be followed by a period of intense cold, such as we have no experience of, even in the Arctic regions. The highest authorities state that the cold during the Moon's long night must reach as low as 250 degrees