Submarines
Created | Updated Apr 14, 2002
Submarines were invented by humans to allow them to stay underwater for very long periods of time without getting the slightest bit wet. Originally invented to research the mysterious ocean depths, it was quickly discovered that there wasn't really that much of interest down there, and the military swiftly became the main owners of submarine-type equipment. One of the many features of your average common-or-garden submarine that is worthy of note is the periscope. The periscope is a pipe that extends from the submarine below the surface, to above the surface and allows those inside the submarine to monitor what is going on upstairs via various imaging techniques, probably involving mirrors. Cunning or what.
