a somewhat lower height than the Black Stone. The choice of the east corner may have had ritual significance; it faces the rain-bringing east wind (al-qabul) and the direction from which Canopus rises. The silver frame around the Black Stone and the black kiswah or cloth enveloping the Kaaba were for centuries maintained by the Ottoman Sultans in their role as Custodian of the Two Holy Mosques. The frames wore out over time due to the constant handling by pilgrims and were periodically replaced. Worn-out frames were brought back to Istanbul, where they are still kept as part of the sacred relics in the Topkapı Palace. Appearance of the Black Stone The Black Stone was described by European travellers to Arabia in the 19th- and early-20th centuries, who visited the Kaaba disguised as pilgrims. Swiss traveller Johann Ludwig Burckhardt visited Mecca in 1814, and provided a detailed description in his 1829 book Travels in Arabia: Visiting the Kaaba in 1853, Richard Francis Burton noted that: Ritter von Laurin, the Austrian consul-general in Egypt, was able to inspect a fragment of the Stone removed by Muhammad Ali in 1817 and reported that it had a pitch-black exterior and a silver-grey, fine-grained interior in which tiny cubes of a bottle-green material were embedded. There are reportedly a few white or yellow spots on the face of the Stone, and it is officially described as being white with the exception of the face. History and tradition The Black Stone was held in reverence well before Islam. It had long been associated with the Kaaba, which was built in the pre-Islamic period and was a site of pilgrimage of Nabataeans who visited the shrine once a year to perform their pilgrimage. The Kaaba held 360 idols of the Meccan gods. The Semitic cultures of the Middle East had a tradition of using unusual stones to mark places of worship, a phenomenon which is reflected in the Hebrew Bible as well as the Quran, while bowing, worshiping and praying to such sacred objects is also described in the Tanakh as idolatrous and was the subject of prophetic rebuke. The meteorite-origin theory of the Black Stone has seen it likened by some writers to the meteorite which was placed and worshipped in the Greek Temple of Artemis. The Kaaba has been associated with fertility rites of Arabia. Some writers remark on the apparent similarity of the