16 in “Y” level (levelling head missing): severely damaged (c.1830).
Used for measuring vertical distance between points in conjunction with a levelling staff.
This instrument was associated with Thomas Carfrae’s land surveying practice in Edinburgh and probably used on his survey of a railway line between Edinburgh and Glasgow for Grainger and Miller in 1830-32. It may also have been used in levelling the water tunnel (constructed c.1820) in the Mound Edinburgh in 1850 for James Leslie CE before the National Gallery was built alongside. Thomas Carfrae’s level book refers.