CHAP. 73. (71.)—WHAT REGULATES THE DAYLIGHT ON THE
EARTH.
Hence it is that there is not any one night and day the same,
in all parts of the earth, at the same time; the intervention of
the globe producing night, and its turning round producing
day[1]. This is known by various observations. In Africa and
in Spain it is made evident by the Towers of Hannibal[2], and in
Asia by the beacons, which, in consequence of their dread of
pirates, the people erected for their protection; for it has been
frequently observed, that the signals, which were lighted at
the sixth hour of the day, were seen at the third hour of the
night by those who were the most remote[3]. Philonides, a
courier of the above-mentioned Alexander, went from Sicyon
to Elis, a distance of 1200 stadia, in nine hours, while he
seldom returned until the third hour of the night, although
the road was down-hill[4]. The reason is, that, in going, he
followed the course of the sun, while on his return, in the
opposite direction, he met the sun and left it behind him.
For the same reason it is, that those who sail to the west,
even on the shortest day, compensate for the difficulty of
sailing in the night and go farther[5], because they sail in the
same direction with the sun.
1. The terms employed in the original are "oppositu" and "ambitu."
Alexandre's explanation of the first is, "quum globi terraquei crassitudo
interposita solis arcet radios;" and of the second, "quum nostra hujus
globi pars a sole ambitur." Lemaire, i. 389.
2. One of these towers is mentioned by Livy, xxxiii. 48; it is said to
have been situated between Acholla and Thapsus, on the sea-coast.
3. Hardouin, according to his usual custom, employs all his learning
and ingenuity to give a plausible explanation of this passage. Alexandre,
as it must be confessed, with but too much reason, remarks, "Frustra
desudavit Harduinus ut sanum aliquem sensum ex illis Plinii deliramentis excuteret." He correctly refers the interval of time, which was
said to occur between these signals, not to any astronomical cause, but to
the necessary delay which took place in the transmission of them. He
concludes, "Sed ad cursum solis hoc referre, dementiæ est. Nam ut tanta
horarum differentia intersit, si moram omnem in speculandis ac
transmittendis signis sustuleris, necesse erit observatores illos
ultimos 135
gradibus, id est, sesquidimidio hemisphærio, a primis distare turribus.
Recte igitur incredibilem Plinii credulitatem ludibrio
vertit Baylius in
Dictionario suo." Lemaire, i. 389.
4. The distance, as here stated, is about 150 miles, which he is said to
have performed in nine hours, but that the same distance, in returning,
required fifteen hours. We have here, as on the former occasion, a note
of Hardouin's to elucidate the statement of the author. On this Alexandre observes, "Optime; sed in tam parva locorum distantia, Elidis et
Sicyonis horologia vix quinque unius hore sexagesimis differre poterant;
quare eunti ac redeunti ne discrimen quidem quadrantis horæ intererat.
Ineptos igitur auctores sequitur hoc quoque loco Plinius." Lemaire, i.
390, 391.
5. "Vincunt spatia nocturnæ navigationis." This expression would
appear to imply, that the author conceived some physical difficulty
in sailing during the night, and so it seems to be understood by
Alexandre;
vide not. in loco.