We cannot tell whether such objects as these were present to the mind of Joel when he spoke of "blood and fire and pillars of smoke"; possibly these metaphors are better explained by a sand- or thunder-storm, especially when we consider that the Hebrew expression for the "pillars of smoke" indicates a resemblance to a palm-tree, as in the spreading out of the head of a sand- or thunder-cloud in the sky. The suggestion has been made,--following the closing lines of _Paradise Lost_ (for Milton is responsible for many of our interpretations of Scripture) "High in front advanced, The brandished sword of God before them blazed, Fierce as a comet," --that a comet was indeed the "flaming sword which turned every way, to keep the way of the tree of life." There is less improbability in the suggestion made by several writers that, when the pestilence wasted Jerusalem, and David offered up the sacrifice of intercession in the threshing floor of Ornan the Jebusite, the king may have seen, in the scimitar-like tail of a comet such as Donati's, God's "minister,"--"a flame of fire,"--"the angel of the Lord stand between the earth and the heaven, having a drawn sword in his hand stretched out over Jerusalem." The late R. A. Proctor describes the wanderings of a comet thus:-- "A comet is seen in the far distant depths of space as a faint and scarcely discernible speck. It draws nearer and nearer with continually increasing velocity, growing continually larger and brighter. Faster and faster it rushes on until it makes its nearest approach to our sun, and then, sweeping round him, it begins its long return voyage into infinite space. As it recedes it grows fainter and fainter, until at length it passes beyond the range of the most powerful telescopes made by man, and is seen no more. It has been seen for the first and last time by the generation of men to whom it has displayed its glories. It has been seen for the first and last time by the race of man itself."[108:1] "These are . . . wandering stars, to whom is reserved the blackness of darkness for ever." FOOTNOTES: [108:1] R. A. Proctor, _The Expanse of Heaven_, p. 134. [Illustration: FALL OF AN AEROLITE. "There fell a great star from heaven, burning as it were a lamp." (_see_ p. 116).] CHAPTER X METEORS Great meteorites--"aerolites" as they are called--are like great comets, chance visitors to our world. Now and then they come, but we cannot foretell their coming. Such an aerolite exploded some fifteen miles above Madrid at about 9{h} 29{m}, on the morning of February 10, 1896:--