What is that swirly bar in front of old barber shops?

Does anyone know what the deal is with the swirly bar that spins in front of old barber shops? How did that trend start, whats the point of it?? I saw one the other day and it's been bugging the hell out of me.What is that swirly bar in front of old barber shops?
The barber pole dates back the middle ages. At that time, barbers not only cut hair, but they were dentists and surgeons. One of the common surgeries in the middle ages was ';bloodletting';... which was the act of cutting the veins in a person's arm to let them bleed out. Bloodletting was done when someone was sick as it was beleived that if you let them bleed out, the sickness would also bleed out.





To do bloodletting, the barber would have the patient tightly grasp a cane which was wrapped in bandages (similar to how a doctor today will have a patient grab a ball when drawing blood). This would cause the veins to pop out and become more visible. The barber would then cut the vein and allow it to bleed. After several mintues of bleeding, the barber would unwrap the bandages from the pole and bandage up the cuts. When the bandages were removed from the patient, they were washed and rewrapped onto the pole for use again. After condinued wrapping and unwarpping, the blood stained along with fresh bandages would look like the red and white barber pole you are familar with.





Eventually barbers were banned from doing surgeries, but the red and white stripped pole had solidified itself as a distinguishable symbol of the barber shop and remains so today.What is that swirly bar in front of old barber shops?
The swirly thing is to tell people if they're open or not if it is spinning they're open if it isn't then then they're closed