Gago Coutinho invented a type of sextant incorporating two spirit levels to provide an artificial horizon.
22.
Common levelling instruments include the spirit level, the dumpy level, the digital level, and the laser level.
23.
Early spirit levels had very slightly curved glass vials with constant inner diameter at each viewing point.
24.
My Christmas spirit level must be low.
25.
"' Plumb Site "'was invented in 1997, and is a feature across Kapro's range of spirit levels.
26.
It is a good idea to hang a spirit level on the line to keep it horizontal.
27.
The spirit level is then rotated through 180 degrees in the horizontal plane, and another reading is noted.
28.
Bradbury said poems in " The Spirit Level " dealt with issues of family history and spiritual well-being.
29.
In this latter case, the plane of rotation of the instrument is levelled, along with the spirit level.
30.
Traditional spirit levels and pendulum-based electronic leveling instruments are usually constrained by only single-axis and narrow tilt measurement range.
