This hands-on activity gives instructions to make a half hour glass with your students that measures time just like on a naval vessel in 1812. It integrates math, using 24-hour time, telling time in other ways besides a clock, and the nautical and naval term of “watches”.
Explore the “Sleeping at Sea” illustration with students. Ask students if they need to do certain tasks at certain times, how do they know the time, and would they be able to know the time if they did not have a clock? Explain to students that sailors on board Constitution relied on a different way to tell time: by a half hour glass and the chiming of bells.
Have students complete the math problem below and fill in the worksheet. Then ask them to fill in the tasks and duties they normally complete in that time period below. Have them compare their tasks to those of an ordinary seaman on Constitution.
Ask students how sailors knew what time it was. Common answers include – watch, clock (which were not reliable at sea due to the rocking and rolling of a ship), stars and sundials (which aren’t consistent due to ship’s movement and changing weather). Prompt them to think about how they know when a turn is up in board games – sand glasses. Time on a ship was rung out every half hour thanks to the use of a half hour glass.
To make a half hour glass with your students, follow the directions: