3446 x 5189 px | 29,2 x 43,9 cm | 11,5 x 17,3 inches | 300dpi
Data acquisizione:
13 maggio 2008
Ubicazione:
Vilanova i la Geltru, Barcelona, Catalunya, Spain
Altre informazioni:
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 masons, bricklayers, other building trades workers, surveyors, millwrights and other metalworkers, and serious videographers. Original spirit levels had two banana-shaped curved glass vials at each viewing point and were much more complicated to use. In the 1920s, Henry Ziemann, the founder of Empire Level, invented the modern level with a single vial. These vials, common on most ordinary levels today, feature 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. Most commonly, spirit levels are employed to indicate how horizontal (level) or how vertical (plumb) a surface is.
