Barber's pole

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A barber's pole is a type of sign used by barbers, most traditionally a pole with a helix of colored stripes (usually red, white, and blue).

Contents 1 Origin in hairdressing and surgery 2 Use in Prostitution 3 Other uses of the term 3.1 Aviation 3.2 Optical illusion 3.3 Computer science 3.4 Web design/development 3.5 Space flight 3.6 Candy 4 See also 5 References 5.1 Sources 5.2 Notes 6 External links

[edit] Origin in hairdressing and surgery

The origin of the barber pole is associated with the service of bloodletting.^[1] During medieval times, barbers 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.

At the Council of Tours in 1163, the clergy was banned from the practice of surgery^[2]. From then, physicians were clearly separated from the surgeons and barbers. Later, the role of the barbers was defined by the College de Saint Come et Saint Damien, established by Jean Pitard in Paris circa 1210^[3], 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 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,[3] started manufacturing barber poles. Marvy made his 50,000th barber pole in 1967, and, by 1996, over 74,000 had been produced. The William Marvy Company is now the sole manufacturer of barber poles in North America. In recent years, the sale of spinning barber poles has dropped considerably, since few barber shops are opening, and many jurisdictions prohibit moving signs.^[1] Koken of St. Louis, MO manufactured Barber equipment such as chairs and assorted poles in the 19th Century.

Spinning barberpoles are supposed to be oriented so that the red (blood) will appear as if it was flowing down.

[edit] Use in Prostitution

In some parts of Asia, a red, white and blue barber pole is used as a symbol for a brothel. While prostitution is illegal in many parts of Asia, laws against it are often not enforced to the degree that all public solicitations for it are eliminated. The barber's pole is used as a euphemistic way of advertising a brothel, thus reducing the likelihood of police intervention.

In South Korea, barber's poles are used both for actual barbershops and for brothels.^[4] Brothels disguised as barbershops, referred to as 이발소 (ilbalso) or 이용실 (iyongsil), are more likely to use two poles next to each other, often spinning in opposite directions, though the use of a single pole for the same reason is also quite common.^[5] Actual barbershops, or 미용실 (miyongsil), are more likely to be hair salons; to avoid confusion, they will usually use a pole that shows a picture of a woman with flowing hair on it with the words "hair salon" written on the pole.

[edit] Other uses of the term

[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 V_MO (Maximum Operating Velocity) or - at altitude - the M_MO (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.^[6]

[edit] Optical illusion

A spinning barber pole is the basis for the 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, giving the illusion of an arch moving upward.

A barber pole motif has been used as a Daymark for lighthouses. See, e.g. White Shoal Light.

[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.

[edit] Web design/development

The term "Barber's Pole" has been used as a metaphor. It identifies 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 [4] during the Apollo 13 accident.

The phrase barberpole continues to be found in many subsystem descriptions in the Space Shuttle News Reference Manual^[7], as well as the NASA/KSC Acronym List.^[8].

[edit] Candy

The old-fashioned American stick candy is sometimes also referred to as "barber pole candy" due to its colorful, swirled appearance.

[edit] See also

• Barber pole illusion
• Shepard tone (musical illusion)

[edit] References

[edit] Sources

• "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

[edit] Notes

This section needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (December 2007)

[edit] External links

Wikimedia Commons has media related to: Barbers poles

• Barber poles at William Marvy Co. (manufacturer)