|The Abney Level is named after Captain William Abney of the School of Military Engineering, Chatham, England. It is also called an "Angle Sextant" & measures the angle of inclination. To observe the level bubble the front end of the telescope extends. Aligning the bubble with a line in the scope helps read the angle of inclination off the vernier scale on the side. A little magnifier helps to read the angle of the scale. The sprit level can be adjusted with two screws on either side.
The Abney level comes with a wooden box. The length of the viewing pipe is 12.8 cm when shut and 18 cm extended. It stands 6cm tall and weighs 180 grams.