of birds. Excellent inns or caravanserais were to be found at
every station; bridges or ferries were established upon all the streams;
guard-houses occurred here and there, and the whole route was kept
secure from the brigands who infested the Empire. Ordinary travellers
were glad to pursue so convenient a line of march; it does not appear,
however, that they could obtain the use of post-horses, even when the
Government was in no need of them.

"_Note._--It was not the distance a horse ridden gently could
accomplish in the entire day, but the distance he could bear to be
galloped once a day. From the account which Herodotus gives of the
post-route between Sardis and Susa, we may gather that the Persians
fixed this distance at about fourteen miles."--George Rawlinson, _The
Five Great Monarchies of the Ancient Eastern World_, London, 1871, vol.
iii. pp. 426-7.

_Roman Empire._

"The advantage of receiving the earliest intelligence, and of conveying
their orders with celerity, induced the Emperors to establish throughout
their extensive dominions the regular institution of posts. Houses were
everywhere erected at the distance only of five or six miles; each of
them was constantly provided with forty horses, and, by the help of
these relays, it was easy to travel an hundred miles in a day along the
Roman roads. The use of the posts was allowed to those who claimed it by
an Imperial mandate; but though originally intended for the public
service, it was sometimes indulged to the business or conveniency of
private citizens (Pliny, though a favourite and a minister, made an
apology for granting post-horses to his wife on the most urgent
business)."--Edward Gibbon, _The History of the Decline and Fall of the
Roman Empire_, London, ed. 1896, vol. i. p. 50.

_Arabia._

"The first traces of the Arabian postal arrangements date from about
fifty years after the death of Mahomed. Calif Mdowija, who died in 679,
is regarded as the founder of the Arabian posts. Kodama, a native of
Bagdad, who died in 959, gives an account of the service in his work
called _The Book of Taxes_. There were 930 postal stations on the six
great highroads starting from Bagdad. At some stations there were relays
of horses, but in Syria and Arabia the messengers rode on camels; and in
Persia the letters were conveyed from station to station by messengers
on foot. The postal service under the Califs was an independent branch
of the administration, and