thumb|200px|Polybolos (reconstruction), a semi-automated arrow thrower, described by Philon
Philo of Byzantium (), also known as
Philo Mechanicus, a
Greek writer on
mechanics, flourished during the latter half of the 2nd century B.C. He was probably younger than
Ctesibius, though some place him a century earlier.
Life and works
Philo was the author of a large work,
Mechanike syntaxis (Compendium of Mechanics), which contained the following sections:
- Limenopoeica - on harbour building.
- Pneumatica - on devices operated by air or water pressure.
- Automatiopoeica - on mechanical toys and diversions.
- Poliorcetica - on siegecraft
- Peri Epistolon - on secret letters
The military sections
Belopoeica and
Poliorcetica are extant in Greek, detailing missiles, the construction of fortresses, provisioning, attack and defence, as are fragments of
Isagoge and
Automatiopoeica (ed. R. Schone, 1893, with German translation in Hermann August Theodor Köchly's
Griechische Kriegs-schriftstelle, vol. i. 1853; E. A. Rochas d'Aiglun,
Poliorcetique des Grecs, 1872).
Another portion of the work, on pneumatic engines, has been preserved in the form of a Latin translation (
De ingeniis spiritualibus) made from an Arabic version (ed. W. Schmidt, with German translation, in the works of
Heron of Alexandria, vol. i., in the
Teubner series, 1899; with French translation by Rochas,
La Science des philosophes... dans l'antiquité, 1882). Further portions probably survive in a derivative form, incorporated into the works of
Vitruvius and of
Arabic authors.
The
Philo line, a geometric construction that can be used to
double the cube, is attributed to Philo.
The treatise
De septem mundi miraculis, on the
Seven Wonders of the World, attributed to Philo of Byzantium, but probably belongs to the 6th century A.D. It is printed in
R. Hercher's edition of Aelian (
Teubner, 1858).
Devices
thumb|Washstand /" class="wiki">automaton working with an escapement mechanism
According to recent research, a section of Philo's
Pneumatics which so far has been regarded as a later Arabic interpolation, includes the first description of a
water mill in history, placing the invention of the water mill in the mid-third century B.C. by the Greeks.
Philon's works also contain the oldest known application of a chain drive in a
repeating crossbow. Two flat-linked chains were connected to a
windlass, which by winding back and forth would automatically fire the machine's arrows until its magazine was empty.
Philon also was the first to describe a
gimbal: an eight-sided
ink pot with an opening on each side could be turnt so that any face is on top, dip in a pen and ink it-yet the ink never runs out through the holes of the side. This was done by the suspension of the inkwell at the center, which was mounted on a series of concentric metal rings which remained stationary no matter which way the pot turns itself.
In his
Pneumatics (chapter 31) Philon describes an
escapement mechanism, the earliest known, as part of a
washstand.
A counterweighted spoon, supplied by a water tank, tips over in a basin when full releasing a pumice in the process. Once the spoon has emptied, it is pulled up again by the counterweight, closing the door on the pumice by the tightening string. Remarkably, Philon's comment that "its construction is similar to that of clocks" indicates that such escapements mechanism were already integrated in ancient water clocks.
Mathematics
In mathematics, Philo tackled the problem of
doubling the cube. The doubling of the cube was necessitated by the following problem, given a catapult, construct a second catapult that is capable of firing a projectile twice as heavy as the projectile of the first catapult. His solution was to find the point of intersection of a rectangular
hyperbola and a
circle, a solution that is similar to
Heron's solution several centuries later.
See also
