Barber's pole
From Wikipedia, the free encyclopedia
A barber's pole is a type of sign used by barbers, a pole with white and red stripes. They have however been known to be of different colors. For example, it was common practice to have black and yellow stripes in the City of Baltimore, Maryland until the early 20th century in honor of the Calvert Colors used by Lord Baltimore.
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[edit] Origin of barber pole in hairdressing and surgery
The origin of the barber pole is associated with the service of bloodletting.[1] During medieval times, barbers also performed surgery on customers as well as tooth extractions. The original pole had a brass basin at the top (representing the vessel in which leeches were kept) and bottom (representing the basin which received the blood). The pole itself represents the staff that the patient gripped during the procedure to encourage blood flow.
In the middle ages in France a decree was issued banning facial hair in men.[citation needed] This helped the barber trade to organise. Later, their role was defined by the College de Saint Come, established in Paris in about 1210, as academic surgeons of the long robe and barber surgeons of the short robe.
The red and white stripes symbolize the bandages used during the procedure: red for the blood-stained and white for the clean bandages. Originally, these bandages were hung out on the pole to dry after washing. As the bandages blew in the wind, they would twist together to form the spiral pattern similar to the stripes in the modern day barber pole. The barber pole became emblematic of the barber/surgeon's profession. Later the cloths were replaced by a painted wooden pole of red and white stripes.
After the formation of the United Barber Surgeon's Company in England, a statute required the barber to use a blue and white pole and the surgeon to use a red pole. In France, surgeons used a red pole with a basin attached to identify their offices. Blue often appears on poles in the United States, possibly as an homage to its national colours. Another more fanciful interpretation of these barber pole colours is that red represents arterial blood, blue is symbolic of venous blood, and white depicts the bandage.
Prior to 1950 there were four manufacturers of barber poles in the United States. In 1950, William Marvy of St. Paul, Minnesota [[1]]started his barber pole manufacturing business. Mr. Marvy made his 50,000th barber pole in 1967, and by the early part of 1996 over 74,000 poles had been produced. The William Marvy Company is the sole remaining manufacturer of barber poles in North America. In recent years, the sale of spinning barber poles has dropped considerably, both because very few new barber shops are opening and many jurisdictions prohibit moving signs of any kind as unsightly or visually disrupting.[1]
[edit] Other uses of the term "barber(s) pole"
[edit] Aviation
The term "on the barber pole" is pilot jargon that refers to flying an aircraft at the maximum safe velocity. The Airspeed Indicator on aircraft capable of flying at altitude features a red/white striped needle resembling a barber pole. This needle displays the VMO (Maximum Operating Velocity) or - at altitude - the MMO (Mach Limit Maximum Operating Speed) of the aircraft. As the aircraft increases in altitude, and the air decreases in density and temperature, the speed of sound also decreases. Close to the speed of sound, an aircraft becomes susceptible to Mach Buffet - shock waves produced by flying so close to the sound barrier. Thus - as the speed of sound decreases, so the maximum safe operating speed of the aircraft is reduced. The "barber pole" needle moves to indicate this speed. Flying "on the barber pole" therefore means to be flying the aircraft as fast as is safe to do so in the current conditions.[2]
[edit] Optical illusion
A spinning barber pole is the basis for a famous motion perception illusion, in which the stripes appear to be traveling down the length of the pole, rather than around it.
In an episode of Dragnet in the 1950s, Friday and Smith stand in front of a barber shop at one point. The shop has a double barber pole and the spirals turn outward, and so the illusion is of an arch moving upward.
[edit] Music (acoustic illusion)
See Shepard tone.
[edit] Computer science
In UI design, a barber pole like pattern is used in progress bars, when the wait time is indefinite. It is intended to be used like a throbber to tell the user that processing is continuing, although it is not known when the processing will complete.
Barber pole is also sometimes used to describe a text pattern where a line of text is rolled left or right one character on the line below. The CHARGEN service generates a form of this pattern. It is used to test RAM, hard disks and printers. A similar pattern is also used in secure erasure of media.
ABCDEFGHIJKLMNOPQRSTUVW BCDEFGHIJKLMNOPQRSTUVWX CDEFGHIJKLMNOPQRSTUVWXY DEFGHIJKLMNOPQRSTUVWXYZ
[edit] Web Design/Development
A request by the client for something "flashy" or clever whether or not it actually adds value to the Web site. It is usually animated, confined to the masthead, and tied in with the logo or theme of the site simply to demonstrate technical grasp of the medium.
[edit] Space Flight
Barberpole is a phrase used to describe the striped output of indicators used during the Apollo and Shuttle programs. Typically the indicator would show all grey or a grey and white striped pattern, known as barberpole, to allow the astronauts a quick visual reference of the status of the spacecraft systems. Various indicators in the Apollo Command Modules indicated barberpole when the corresponding system was inactive. Astronaut Jim Lovell can also be found describing system indications as 'barber poled' in the transcript of radio transmissions [3] during the Apollo 13 Accident.
The phrase barberpole continues to be found in many subsytem descriptions in the Space Shuttle News Reference Manual [4], as well as the NASA/KSC Acronym List (under BP) [5].
[edit] References
- ^ a b "History of Barber Poles" page of Barberpolesdirect.com.
- "The Sign of the Barber Pole". John H. Lienhard. The Engines of Our Ingenuity. NPR. KUHF-FM Houston. 2001. No. 1635. Transcript.
- "Blood, Bandages and Barber Poles", in The Guide to Life, The Universe and Everything, BBC, November 29, 2002. Accessed December 27, 2005
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