[CHAPTER VI.]
PHENOMENA SUPPOSED TO BE METEORIC—METEORIC DUST—DARK DAYS.
It is well known that great variety has been found in the composition of aerolites. While some are extremely hard, others are of such a nature as to be easily reducible to powder. It is not impossible that when some of the latter class explode in the atmosphere they are completely pulverized, so that, reaching the earth in extremely minute particles, they are never discovered. It is very unlikely, moreover, that of the millions of shooting-stars that daily penetrate the atmosphere nothing whatever in the solid form should ever reach the earth's surface. Indeed, the celebrated Reichenbach, who devoted great attention to this subject, believed that he had actually discovered such deposits of meteoric matter. Chladni and others have detailed instances of the fall of dust, supposed to be meteoric, from the upper regions of the atmosphere. The following may be regarded, with more or less probability, as instances of such phenomena:
1. A.D. 475, November 5th or 6th. A shower of black dust fell in the vicinity of Constantinople. Immediately before or about the time of the fall, according to old accounts, "the heavens appeared to be on fire," which seems to indicate a meteoric display of an extraordinary character.
2. On the 3d of December, 1586, a considerable quantity of dark-colored matter fell from the atmosphere, at Verde, in Hanover. The fall was attended by intense light, as well as by a loud report resembling thunder. The substance which fell was hot when it reached the earth, as the planks on which a portion of it was found were slightly burnt, or charred. The date of this occurrence, allowance being made for the movement of the node, is included within the limits of the meteoric epoch of December 6th–13th.
3. About a century later, viz., on the 31st of January, 1686, a very extensive deposit of blackish matter, in appearance somewhat resembling charred paper, took place in Norway and other countries in the north of Europe. A portion of this substance, which had been carefully preserved, was analyzed by Grotthus, and found to contain iron, silica, and other elements frequently met with in aerolites.
4. On the 15th of November, 1755, red rain fell in Sweden and Russia, and on the same day in Switzerland. It gave a reddish color to the waters of Lake Constance, to which it also imparted an acid taste. The rain which fell on this occasion deposited a sediment whose particles were attracted by the magnet.
5. In 1791 a luminous meteor exploded over the Atlantic Ocean, and at the same time a quantity of matter resembling sand descended to the surface.
6. According to Chladni the explosion of a large bolide over Peru, on the 27th of August, 1792, was followed by a shower of cindery matter, the fall of which continued during three consecutive days.
7. On the 13th and 14th of March, 1813, a shower of red dust fell in Calabria, Tuscany, and Friuli. The deposit was sufficient to impart its color to the snow which was then upon the ground. That this dust was meteoric can scarcely be doubted, since at the same time a shower of aerolites fell at Cutro, in Calabria, attended by two loud reports resembling thunder. The shower of dust continued several hours, and was accompanied by a noise which was compared to the distant dashing of the waves of the ocean.[19]