3/internal/media/dispatcher/13604/fullHourglassMMM 0053154890851191/internal/media/dispatcher/7361/fullHourglassMMM 004761489575881An hourglass made of two pear-shaped bulbs of Glass united at their apexes held by a circular ring of Glass, having a narrow passage between them, allowing the sand to flow through. The bulbs were normally bound together using twine or wax but at the end of the eighteenth century one single Glass vessel was blown. The bulbs are held within a wooden framework. Also known as sandglass, log Glass or watch Glass, they were normally constructed to run for a period of half an hour. For maritime purposes, half-minute, half-hour, hour and four hour sand Glasses were manufactured. At sea, an hour Glass was used by the seaman to mark his four-hour watches, where there were six watches in a day, each watch being split into eight bells. The ship's boy used to turn the hourglass and ring the bell. After eight bells, the watch was changed./internal/media/dispatcher/7366/fullHourglass with RopeMMM 004762489576882An hourglass made of two pear-shaped bulbs of Glass united at their apexes, having a narrow passage between them, allowing the pink sand to flow through. The bulbs were normally bound together using twine or wax but at the end of the eighteenth century one single Glass vessel was blown. The bulbs are held within a wooden framework, which is surrounded by rope forming into a loop on either side, serving as a hanging device. Also known as sandglass, log Glass or watch Glass, they were normally constructed to run for a period of half an hour. For maritime purposes, half-minute, half-hour, hour and four hour sand Glasses were manufactured. At sea, an hour Glass was used by the seaman to mark his four-hour watches, where there were six watches in a day, each watch being split into eight bells. The ship's boy used to turn the hourglass and ring the bell. After eight bells, the watch was changed.