The Gyro is a Greek-American sandwich consisting of well- seasoned ground meat, usually beef or lamb, cooked on a slow turning vertical spit. Gyro, as in gyroscope, comes from the Greek word gyrizo, meaning "to rotate". As the meat is cooked, thin slices are shaved off and placed in or on pita bread. The sandwich is garnished with diced tomato, lettuce and onions and topped with a sauce of diced cucumbers in yogurt (Tsatziki). This type of sandwich has been found in Greece, Turkey and the Middle East since the time of Alexander the Great when his soldiers used their long knlves to skewer and continue to turn meat over fire until cooked.The Greek Gyro was derived from the Turkish Doner Kabab which was invented in Bursa, Turkey and introduced into Greece in the 1970's, either from the Toumba district of Thessaloniki, as one story suggests, or from a cook from Constantinople in the 1950's.The Doner Kabab, however, consists of sliced, not ground, meat layered on a vertical spit and roasted on a vertical grill. The Gyro was first introduced to the American public by George Apostolou in 1965 at the Parkview Restaurant, Chicago, IL, which was owned byApostolou and his cousin. The new sandwich became popular and other restaurants wanted to offer Gyros as alternatives to the ubiquitous hamburger. Apostolou began to manufacture Gyros in large quantities to sell to other restaurants and the demand became so great that George sold his restaurant and opened a U.S.D.A. approved Gyros factory in 1975. From that beginning,Gyros became available and enjoyed throughout the United States. In spite of its popularity, the Gyro is one of the most mispronounced of any food item, being pronounced "jee-ros", "jai-ros" or "gee-ros"when the correct Greek pronunciation is 'Yeh-ro". There is no true letter G, in the English sense, in the Greek language and the Greek letter gamma is pronounced "yeh".