Archaeological dating history
1947: Upward trend in world production of aluminum begun (Encyclopedia Britannica 1973 (1): 694).1820-1925: Tooled finish (Jones and Sullivan 1985: 165). Different cultures around the world record time in different fashions.According to the Gregorian calendar, it is the year 2009 AD. The Kaliyuga Hindu Calendar maintains it is 5110, the Islamic calendar 1430 and the Persian, 2630.
1886: Modern electrolytic method of producing aluminum discovered by Charles Martin Hall in the United States and Paul L. Heroult in France (Encyclopedia Britannica 1973 (1): 693). 1920: Beginning of commercial production of aluminum foil; used to wrap tea, candy, gum and cigarettes (Sacharow 191).This is something that the archaeologist himself is rarely equipped to do; he has to rely on colleagues specializing in geology, ; and he established as a fact of prehistory that over 4,000 years ago these large stones had been transported 200 miles from west Wales to Salisbury Plain.