On the Nature and Causes of Earthquakes
(Extract from Conrad of Megenburg's "Buch der Natur," 1359)
The fourth and nethermost element is the sphere of earth. Its distance from the firmament [of the fixed stars], as determined by divers scientific men, both pagan and Christian, is 309,375 miles. No one can impugn the accuracy of this result, depending as it does upon laborious calculation and the reduction of very delicate astronomical observations. None but unlettered folk contemn such investigations. Ignorant persons are unable to comprehend that a geometer may station himself outside the town and accurately determine the height of turrets within the town by means of angular measurement. Yet in sooth is it possible. By a similar method we ascertain the distance from earth to the starry heavens.
The earth is the only one of the four elements that is favorably adapted for man; it is peculiarly his province, as heaven is the habitation of God and the angels. The earth element alone is innocuous to man, the others often injure him. For water drowns, foul air suffocates, and fire consumes him. The earth is by nature cold and dry, externally harsh, yet concealing within its bosom full many beauteous things, such as precious stones and the noble metals. By a like token, many an humble citizen may possess jewels within his heart. The earth-realm is very luxuriant, and the only one that brings forth fruit in abundance. How many miles it measures in circumference, and the extent of its diameter, I have already set forth in another place,[1] and likewise have explained the cause thereof, why it does not fall away from its abode in space. As the heart is lodged within the mid-portion of the body, so is hell seated at the center of the earth. Thus do our reverend masters instruct us.[2]
Oft it happens that the earth trembles, causing cities to fall, and mountains to crash together. Simple folk know not the reason of this, but foolishly believe that the earth is borne up by a mighty fish, which carries his tail in his mouth; and the turning or moving about of this creature causes the earth to shake. But this is a myth.[3] Remains for
- ↑ Conrad's data as to the dimensions of the earth and its distance from the several heavens are possibly derived from the same source as Dante's and Brunette Latini's, namely, the Elementa Astronomica of Alfraganus, cap. xxi. Roger Bacon's calculation of the earth's circumference was only one-fourteenth smaller than the truth, and Ristoro's independent reckoning of the latitude of Arezzo, in 1282, was in error to the extent of little more than one degree.
- ↑ S. Thomas Aquinas teaches with regard to hell that it is probably situated under the earth and that its fire is of the same kind as terrestrial fire, an ignis corporeus. (Summa theol., Suppl., Pars iii., Qu. 97.)
- ↑ Probably an echo of ancient Titan myths, though having affinity also with the Arabian voyages of Sinbad. The existence of a great sea-monster was a very popular legend in the middle ages, the creature being sometimes identified
