The only other allusion in the poem to a comet is near its conclusion, when the Cherubim descend to take possession of the Garden, prior to the removal of Adam and Eve—
High in front advanced,
The brandished sword of God before them blazed,
Fierce as a comet; which with torrid heat,
And vapour as the Lybian air adust
Began to parch that temperate clime.—xii. 632-36.
FALLING STARS
On any clear night an observer can, by attentively watching the heavens, perceive a few of those objects which become visible for a moment as a streak of light and then vanish. They are the result of the combustion of small meteoric masses having a celestial origin, and travelling with cosmical velocity, and which, in their headlong flight, become so heated by contact with the Earth’s atmosphere that they are converted into glowing vapour. This vapour when it cools condenses into fine powder or dust, and gradually descends upon the Earth’s surface, where it can be detected.
Shooting stars become visible at a height varying between twenty and one hundred and thirty miles, and their average velocity has been estimated at about thirty miles a second. Though casual falling stars can be seen at all times in every part of the heavens, yet there are certain periods at which they appear in large numbers, and have been observed to radiate from certain well-defined parts of the sky. When the radiant point is overhead, the falling stars spread out and resemble a parachute of fire; but when it is below the horizon, the stars ascend upwards like rockets into the sky. The radiant point is fixed among the stars, so that at the commencement of a shower it may be overhead, and before the termination of the display it may have travelled below the horizon. The radiant is usually named after the constellation in which it is observed.
The November meteors are called Leonids, because they radiate from a point in the constellation Leo; those in Taurus are called Taurids; in Perseus, Perseids; in Lyra, Lyraïds; and in Andromeda, Andromedes, because their radiant points are situated in those constellations.
The falling stars that have attracted most attention are those which appear on or about November 13. Every year at this period they can be seen in greater or less numbers, and on referring to numerous past records it has been ascertained that a magnificent display of those objects occurs every thirty-three years. The earliest historical allusion to this meteoric shower is by Theophanes, who wrote that in the year 472 A.D. the sky at Constantinople appeared to be on fire with falling stars. In the year 902 A.D. another remarkable display took place, and from that time until 1833 twelve conspicuous displays are recorded as having occurred at recurring intervals of thirty-three years. The grandest display of this kind that was ever witnessed occurred in 1833. It was visible over nearly the whole of the American continent, and, having commenced at midnight, lasted for four or five hours. The falling stars were so numerous that they appeared to rain upon the Earth, and caused the utmost consternation and terror among those who witnessed the phenomenon, many persons having imagined that the end of the world was at hand. The regular recurrence of these meteoric displays has been satisfactorily explained by the assumption that round the Sun there travels in an elliptical orbit with planetary velocity a vast shoal of meteoric bodies some millions of miles in length and several hundred thousand miles in breadth. The nearest point of their orbit to the Sun coincides with the Earth’s orbit, and the most distant part extends beyond the orbit of Uranus. These bodies accomplish a circuit of their orbit in 33¼ years. The Earth in her annual revolution intersects the path of the meteors, and when this occurs some falling stars can always be seen; but when the intersection happens at the time the shoal is passing, then there results a grand meteoric display. Numerous other meteoric swarms travel in orbital paths round the Sun.
Milton, in his poem, alludes to falling stars upon two occasions. In describing the fall of Mulciber from Heaven he says:—
from morn
To noon he fell, from noon to dewy eve,
A summer’s day; and with the setting sun
Dropt from the zenith like a falling star,
On Lemnos the Ægaean isle.—i. 742-46.
The rapid flight of the archangel Uriel from the Sun to the Earth is described in the following lines:—