A pocket sundial is a portable instrument that tells the time based on the position of the sun. Here's a brief description of how it works: 1. Orientation: Hold the pocket sundial horizontally and point the gnomon (a small stick or rod) toward the sun. 2. Shadow Casting: The gnomon casts a shadow on the dial plate of the sundial. The position of the shadow corresponds to the time. 3. Hour Lines: The dial plate of the sundial is marked with hour lines. These lines are designed to align with the position of the shadow at specific times of the day. By observing where the shadow falls on the dial, you can read the approximate time. 4. Adjusting for Latitude: Pocket sundials are designed for specific latitudes, so it's important to adjust them accordingly for accurate readings. Latitude adjustment can be done by tilting the sundial to the correct angle or using additional markings on the dial plate. It's essential to note that pocket sundials are not as precise as modern clocks or watches, as they rely on the sun's position, which can be influenced by factors like the time of year and weather conditions. Nevertheless, they can provide a general sense of time when used properly