106 plint's natural histoet. [Book II, courier of the above-mentioned Alexander, went from Sicjon 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 do^Ti-hilP. 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", because they sail in the same direction with the sun. CHAP. 74. (72.) — REMARKS OK DIALS, AS CONNECTED WITH THIS SUBJECT. The same dial-plates^ cannot be used in all places, the shadow of the sun being sensibly different at distances of 300, or at most of 500 stadia"*. Hence the shadow of the dial- pin, which is termed the gnomon, at noon and at the summer solstice, in Egypt, is a little more than half the length of the gnomon itself. At the city of Home it is only -g less than the gnomon, at Ancona not more than -^j less, while in the part of Italy which is called Venetia, at the same hour, the shadow is equal to the length of the gnomon^. ^ The distance, as here stated, is about 150 miles, which he is said to have performed m nine hours, but that the same distance, in retm-ning, 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 Alex- andre observes, " Optime ; sed in tam parva locorum distantia, Ehdis et Sicyonis horologia vix qumque unius horse sexagesimis diiFerre poterant ; quare eunti ac redeunti ne discrimen quidem quadrantis liora; intererat. Ineptos igitur auctores sequitur hoc quoque loco Plinius." Lemaire, i. 390, 391. 2 " Vincunt spatia noctumae navigationis." Tliis expression would ap- pear to imply, that the author conceived some physical difficulty m sail- ing during the night, and so it seems to be understood by Alexandre ; vide not. in loco. ^ " Vasa horoscopica." " Yasa horoscopica appeUat horologia in piano descripta, horizonti ad Hbellam respondentia. Vasa dicmitur, quod area in qua hneae ducebantur, labri interdum instar et conchse erat, cujus in margine describebantvir bora?. Horoscopa, ab cop a et c/co Trtw, hoc est, ab uispiciendis horis." Hardouin, in Lemaire, i. 391. ■* These distances are respectively about 38 and 62 mUes.
- We are not to expect any great accuracy in these estimates, and we
accordingly find, that our author, when referring to the subject in hia
