将手表横放。 将时针对准太阳。 均分时针与12点刻度之间的夹角，找到南方。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
This trick can be used anywhere in the Northern Hemisphere during the day, when the sun is visible. Lay the watch flat and face-up in your palm so that its face is parallel with the ground. Turn the watch, your hand, or your entire body so that the hour hand of your watch is pointing directly at the sun. The time on the watch doesn't matter, as long as it's accurate. If you're having a hard time lining the hour hand up with the sun exactly, you may want to use a narrow object's shadow to help yo