106 
plii^t's natueal htstoet. 
[Book IT. 
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 down-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.) — KEMAEKS OK DIALS, AS COKKECTED 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 Rome it is only -J 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 in nine horn's, 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 Alex- 
andre observes, " Optime ; sed in tam parva locorum distantia, Ehdis et 
Sicyonis horologia vix qumque unius horse sexagesimis differre poterant ; 
quare eunti ac redeunti ne discrimen quidem quadrantis horse intererat. 
Ineptos igitur auctores sequitur hoc quoque loco Plinius." Lemaire, i. 
390, 391. 
2 " Vincunt spatia nocturnse navigationis." This expression would ap- 
pear to imply, that the author conceived some physical difficulty in sail- 
ing during the night, and so it seems to be understood by Alexandre ; 
vide not. in loco, 
3 " Yasa horoscopica." " Yasa horoscopica appeUat horologia in piano 
descripta, horizonti ad Ubellam respondentia. Yasa dicuntur, quod area 
in qua hnese ducebantur, labri inter dima ins tar et conchse erat, cujus in 
margine describebantur horse. Horoscopa, ab lopa et (tkottgo), hoc est, 
ab inspiciendis horis." Hardouin, in Lemaire, i. 391. 
4 These distances are respectively about 38 and 62 miles. 
^ We are not to expect any great accuracy in these estimates, and we 
accordingly find, that our author, when referring to the subject in his 
