Vintage Yelland Abney Hand Level Pocket Clinometer with Original Leather Case

Title: Vintage Yelland Abney Hand Level Pocket Clinometer with Original Leather Case.
Manufacturer: Yelland, circa 1980's.
Height: 5.3cm.
Length: 12.5cm.
Width: 3.0cm.
Info: Abney Hand Held Pocket Clinometer / Inclinometer Level, with Minutes and Degrees.
Square body for levelling on the measured surface, with original shaped leather case.
The semi circular dial with 60 degree vernier scale and separate 1 in 1 to 1 in 10 scale.
Above the body is a spirit level tube which is tilted by the centre wheel, the height to be determined is sighted through the instrument and the bubble tube is tilted until the bubble, viewed in the mirror in the sighting tube, is brought level with the top of the sighted object.
The mirror is polished solid silver, removable for cleaning, the sighting tube extends for greater accuracy.
All in very good condition and working order, some wear to the powder coated body.
The steel angle scale reads from (minus) -90 degrees to (plus) +90 degrees, with an inner 0 - 100 % scale.
Clinometers can still be used for: 
Topographic surveying, to place high precision surveying equipment, particularly in rough terrain.
In forestry, for tree height measurement.
In mining and mine safety inspection, to measure the grades of haulage roads.
In geology, in measurements of rock outcrops and fault scarps.
The leather case in good condition with some wear from inscribing and usage.
Based on a design by Capt. Abney which was registered in 1884 and manufactured by Elliott Bros. 
(London Abneys Level Rd 5205 No 165 Elliot London)
Condition: Previously used on site, in good working condition, with Original case, all parts in working order, no missing items.
Price: R 995.00 Inc Vat.