Locking mechanism

[Tetley]

For a genius to understand. This device works well in the dark.

But only when the moon is new on any day between Wednesday and Thursday. You also have to watch the pressure tend and the prevailing wind direction.

Just in case you'd forgotten about that.

[Carolina Kiltman]

However, the thing only works in the Northern hemisphere. If you live in the Southern latitudes, then you must reverse the threads or it will loosen by itself and quit working.