An hourglass (sandglass, sand timer, sand watch, sand clock, egg timer) measures the passage of a few minutes or an hour of time. For example, the American television soap opera Days of our Lives, since its first broadcast in 1965, has displayed an hourglass in its opening credits, with the narration, "Like sands through the hourglass, so are the days of our lives," spoken by Macdonald Carey. The first hourglasses were two separate bulbs with a cord wrapped at their union that was then coated in wax to hold the piece together and let sand flow in between. Unlike its predecessor the clepsydra, or water clock, which may have been invented in ancient Egypt, the hourglass is believed to have originated in medieval Europe.