Originally Posted by
tfar
I also read about another useful feature of a watch with an extra 24h hand. You can use it as a compass. Point the 12h hand at the sun and the 24h hand will point north. Of course, this presupposes that you set them to the same time zone. Don't blame me if you get lost in the desert!
Only if you're in the northern hemisphere - here down under it will point south.
Also gets inaccurate if you're in the tropics (by which I mean between the Tropic of Cancer and the Tropic of Capricorn) or early or late in the day.
Audrey
PS: and you can do the same thing with a normal watch - point the hour hand at the sun and North or South is half-way between the hand and 12 noon.