HISTORY OF THE BUBBLE LEVEL
A spirit level or bubble level is an instrument designed to indicate whether a surface is level or plumb. Different types of spirit levels are used by carpenters, stone mason, bricklayers, other building trades workers. The spirit level was invented by Melchisedech Thevenot in 1661, but it was not widely available until the mid-1800’s, thus it is a relatively new addition to construction sites. For thousands of years, builders leveled up their work with either a simple water level or a plumb bob attached to a frame. In the mid 1800’s the single vial became popular and is common on most ordinary levels today, featuring a slightly curved glass tube which is incompletely filled with a liquid, usually a yellow-colored ‘spirit’ (a synonym for Ethanol), leaving a bubble in the tube. Ethanol is used because of its low freezing point, -114°c. which prevents it from freezing in cold weather. Where a spirit level must also be usable upside-down, the banana-shaped tube is replaced by a barrel-shaped tube. The upper internal surface of the tube is thus always of the appropriate shape. Through the years quality levels have been made from various woods & metals, some with emphasis on practicality, others on ornateness and beauty, but all on accuracy. |
