Philo of Byzantium
Encyclopedia
Philo of Byzantium also known as Philo Mechanicus, was a Greek
Greeks
The Greeks, also known as the Hellenes , are a nation and ethnic group native to Greece, Cyprus and neighboring regions. They also form a significant diaspora, with Greek communities established around the world....

 engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

 and writer
Writer
A writer is a person who produces literature, such as novels, short stories, plays, screenplays, poetry, or other literary art. Skilled writers are able to use language to portray ideas and images....

 on mechanics
Mechanics
Mechanics is the branch of physics concerned with the behavior of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment....

, who lived during the latter half of the 3rd century BC. He was probably younger than Ctesibius
Ctesibius
Ctesibius or Ktesibios or Tesibius was a Greek inventor and mathematician in Alexandria, Ptolemaic Egypt. He wrote the first treatises on the science of compressed air and its uses in pumps...

, 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:
  • Isagoge (εἰσαγωγή) - an introduction to mathematics
    Mathematics
    Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

  • Mochlica (μοχλικά) - on general mechanics
    Mechanics
    Mechanics is the branch of physics concerned with the behavior of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment....

  • Limenopoeica (λιμενοποιικά) - on harbour building
  • Belopoeica (βελοποιικά) - on artillery
    Artillery
    Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...

  • Pneumatica (πνευματικά) - on devices operated by air or water pressure
  • Automatopoeica (αὐτοματοποιητικά) - on mechanical toys and diversions

  • Parasceuastica (παρασκευαστικά) - preparation for sieges
  • Poliorcetica (πολιορκητικά) - on siegecraft
  • Peri Epistolon (περὶ ἐπιστολῶν) - 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 Automatopoeica (ed. R. Schone, 1893, with German translation in Hermann August Theodor Köchly's Griechische Kriegsschriftsteller, 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
Vitruvius
Marcus Vitruvius Pollio was a Roman writer, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work De Architectura ....

 and of Arabic authors.

The Philo line
Philo line
In geometry, the Philo line is a line segment defined from an angle and a point. The Philo line for a point P that lies inside an angle with edges d and e is the shortest line segment that passes through P and has its endpoints on d and e...

, a geometric construction that can be used to double the cube
Doubling the cube
Doubling the cube is one of the three most famous geometric problems unsolvable by compass and straightedge construction...

, is attributed to Philo.

A treatise conventionally titled De septem mundi miraculis, on the Seven Wonders of the World, is ascribed to Philo of Byzantium, but belongs to a much later date, probably the 6th century A.D. It is printed in R. Hercher's edition of Aelian (Teubner, 1858); an English translation by Jean Blackwood is included as an appendix in The Seven Wonders of the World by Michael Ashley (Glasgow: Fontana Paperbacks, 1980).

Devices

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
Repeating crossbow
A repeating crossbow is a crossbow where the separate actions of stringing the bow, placing the bolt and shooting it can be accomplished with a simple one-handed movement while keeping the crossbow stationary. This allows a higher rate of fire than a normal crossbow...

. Two flat-linked chains were connected to a windlass
Windlass
The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder , which is rotated by the turn of a crank or belt...

, 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
Gimbal
A gimbal is a pivoted support that allows the rotation of an object about a single axis. A set of two gimbals, one mounted on the other with pivot axes orthogonal, may be used to allow an object mounted on the innermost gimbal to remain immobile regardless of the motion of its support...

: an eight-sided ink
Ink
Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...

 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
Escapement
In mechanical watches and clocks, an escapement is a device that transfers energy to the timekeeping element and enables counting the number of oscillations of the timekeeping element...

 mechanism, the earliest known, as part of a washstand
Washstand
A washstand is a table or stand containing conveniences for washing oneself.- Ancient Greece:In his Pneumatics, Philo of Byzantium, a Greek engineer and writer on mechanics, 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
Doubling the cube
Doubling the cube is one of the three most famous geometric problems unsolvable by compass and straightedge construction...

. 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
Hyperbola
In mathematics a hyperbola is a curve, specifically a smooth curve that lies in a plane, which can be defined either by its geometric properties or by the kinds of equations for which it is the solution set. A hyperbola has two pieces, called connected components or branches, which are mirror...

 and a circle
Circle
A circle is a simple shape of Euclidean geometry consisting of those points in a plane that are a given distance from a given point, the centre. The distance between any of the points and the centre is called the radius....

, a solution that is similar to Heron's
Hero of Alexandria
Hero of Alexandria was an ancient Greek mathematician and engineerEnc. Britannica 2007, "Heron of Alexandria" who was active in his native city of Alexandria, Roman Egypt...

solution several centuries later.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK