The clinometer is an optical device for measuring elevation angles above a horizontal line. In an Abney clinometer, the object sighted and the level bubble can be seen simultaneously. This instrument enables the surveyor to rotate the horizontal bubble vial through ±60 degrees to measure inclination. The arc is divided to single degrees and reading by vernier to 1 arcminutes. Gradients are adjusted with a wheel attached to the spirit level while correcting the position of the bubble. The abney level is market 'Treacher and Co. ltd Bombay & Poona' and 'Made in England' Bombay and Poona 'Made in England' The level comes in its original box with puple velvet and silk lining.