Ordnance survey of Scotland.
Great Britain.Ordnance Survey.
Southampton : Ordnance Survey Office,
1856-1887.
Surveyed 1845-78.
Sheets numbered 1 - 131, but with extra 57A.
Maps are in either of 2 types - relief shown by hachures or contours/outline.
The maps were reprinted over a period of years and there may be several different issues of each sheet available.
For full holdings see paper indexes in Map Room.