Your iPhone's compass is a feature you may not know about, but it can save your life. However, you'll need to calibrate it ...

so make sure you practice in a familiar area before setting out into the wild. The post How to use a compass for navigation when GPS fails appeared first on The Manual.

Primarily, the compass was used for geomancy for a long time before it was used for navigation Ancient Chinese alchemists realized that the magnetite ore would point towards a magnetic north. Their ...