Spirit level
// November 7th, 2009 // measurement tools
This tool is usually made of a straight piece of wood or metal with a rectangular glass section filled with oil. The oil has a bubble suspended in it, which should maintain a central position between two marked lines to indicate when the level is resting in an exact horizontal or vertical position. Event though spirit levels are most commonly used for bricklaying, they can also be used in woodworking to double-check that a surface is level, particularly for larger projects, such as a table. 
