PART III. A VOYAGE TO LAPUTA, BALNIBARBI, LUGGNAGG, GLUBBDUBDRIB, AND JAPAN.
3. CHAPTER III.
[A phenomenon solved by modern philosophy and astronomy. The
Laputians' great improvements in the latter. The king's method of
I desired leave of this prince to see the curiosities of the
island, which he was graciously pleased to grant, and ordered my
tutor to attend me. I chiefly wanted to know, to what cause, in
art or in nature, it owed its several motions, whereof I will now
give a philosophical account to the reader.
The flying or floating island is exactly circular, its diameter
7837 yards, or about four miles and a half, and consequently
contains ten thousand acres. It is three hundred yards thick. The
bottom, or under surface, which appears to those who view it below,
is one even regular plate of adamant, shooting up to the height of
about two hundred yards. Above it lie the several minerals in
their usual order, and over all is a coat of rich mould, ten or
twelve feet deep. The declivity of the upper surface, from the
circumference to the centre, is the natural cause why all the dews
and rains, which fall upon the island, are conveyed in small
rivulets toward the middle, where they are emptied into four large
basins, each of about half a mile in circuit, and two hundred yards
distant from the centre. From these basins the water is
continually exhaled by the sun in the daytime, which effectually
prevents their overflowing. Besides, as it is in the power of the
monarch to raise the island above the region of clouds and vapours,
he can prevent the falling of dews and rain whenever he pleases.
For the highest clouds cannot rise above two miles, as naturalists
agree, at least they were never known to do so in that country.
At the centre of the island there is a chasm about fifty yards in
diameter, whence the astronomers descend into a large dome, which
is therefore called flandona gagnole, or the astronomer's cave,
situated at the depth of a hundred yards beneath the upper surface
of the adamant. In this cave are twenty lamps continually burning,
which, from the reflection of the adamant, cast a strong light into
every part. The place is stored with great variety of sextants,
quadrants, telescopes, astrolabes, and other astronomical
instruments. But the greatest curiosity, upon which the fate of
the island depends, is a loadstone of a prodigious size, in shape
resembling a weaver's shuttle. It is in length six yards, and in
the thickest part at least three yards over. This magnet is
sustained by a very strong axle of adamant passing through its
middle, upon which it plays, and is poised so exactly that the
weakest hand can turn it. It is hooped round with a hollow
cylinder of adamant, four feet yards in diameter, placed
horizontally, and supported by eight adamantine feet, each six
yards high. In the middle of the concave side, there is a groove
twelve inches deep, in which the extremities of the axle are
lodged, and turned round as there is occasion.