A spirit level is a must if you want your home to have straight, even lines, but what is that bright-green liquid inside the bubbles? It's not just water.

When a bubble, or spirit, level is level, what does that mean relative to Earth? Pat French Longdon-upon-Tern, Shropshire, UK There is a well-known story of a gentleman who held that Earth was flat.

Wondering when to level a lawn? An uneven surface is an obvious clue, but there are actually a few different signs to watch out for. If you’re wondering if it’s time to learn how to level your ...