Casquets lighthouses per ton of ship when vessels passed the rocks and in turn he paid Trinity House 50 pounds per year for the right to run the lighthouses. The lighthouses reverted to Trinity House in 1785. They were converted to oil lamps with metal reflectors which were first used on 25 November 1790; and upgraded again with apparatus to rotate a beam of light in 1818. This had a clockwork mechanism which was wound up every hour and a half and gave one flash every 15 seconds. The lighthouses were badly damaged and the lanterns smashed in a severe storm on
Lighthouses on the Isle of Arran act in 1786, just 4 lighthouses existed in the whole of Scotland. Over the course of the following 200 years, the NLB expanded greatly and is now responsible for 206 lighthouses, 163 buoys, 29 beacons, 2 supply and maintenance ships and a variety of other traditional and modern navigational aids. For a long time, lighthouses mostly burned wood, coal and candles before oil became predominant. Oil was mostly used in the form of whale oil and colza oil before the introduction of kerosene in the mid 19th century and eventually electricity. Mainland stations excepted, lights were mostly manned by 3