PM-732 ABNEY LEVEL

For measurement of heights and setting of slopes and falls.
Polished brass arc 74 mm. diameter divided 90-0-90°C with vernier
scale reading to 10 min. of arc operated by knurled knob which also
carries the spirit level. Gradient scale 0-10 x 1. With a magnifier lens
for easy viewing of scale. Sighting tube of square-section brass 125
mm. long.