The idea that tumblers would spill if set down is not the only possible explanation. Some sources believe the opposite -- they claim that tumblers were weighted at the bottom so that they would automatically right themselves if knocked over. This view dates to at least the late 19th century and is advocated by some antiques experts today. As a third option, an 18th-century etymologist suggested that the word "chalice" for a drinking glass originated from a Greek word meaning "to roll around."