Where can I find information about Harbour or Canal Police?

Under the Police (Scotland) Act 1858 (21 & 22 Vict., c.65) the sheriff of a county in which a canal or other public work was in the course of construction was empowered to direct the chief constable to appoint additional constables to keep the peace and ensure the security of persons and property from crimes and unlawful acts within the limits of such public works and a radius of one mile therefrom. Under the Harbours, Docks and Piers Act, 1847 (10 & 11 Vict., c.27), provision was made for the appointment of special constables within the limits of a harbour, dock or pier and a mile beyond, but in the larger Scottish ports police duty in the harbours was normally undertaken by constables supplied by the chief constable of the burgh. Therefore, you should look for information in the records of the burgh or county constabulary concerned. Two forces on the River Clyde briefly operated in the mid-19th century. The Clyde River Police was formed 1862 and merged with the Glasgow City force in 1867. The Greenock Harbour Police operated between 1817 and 1822, and, again between 1825 and 1843. It was absorbed by the Greenock Burgh Constabulary.