Robert Stevenson (8 June 1772 – 12 July 1850), the grandfather of the author Robert Louis Stevenson, was a Scottish lighthouse engineer. He built twenty-three lighthouses in Scotland alone, including Bell Rock lighthouse.
In the summer of 1801, Stevenson embarked on an eight-week tour of the English lighthouses. His diary of that journey, along with later trips in 1813 and 1818, was edited by his great-grandson D. Alan Stevenson, and published by Thomas Nelson and Sons in 1946, under the title “English Lighthouse Tours”.
This is Stevenson’s account of his visit to the Liverpool lighthouses.
From the Isle of Man I went in the Packet to Liverpool, and in my way thence to the lights on the Smalls and at Milford Haven, I took Bidston Hill and Sea Lights, the Lake (Hoylake) lights, Point of Air light and the Skerries light. Bidston Hill and Sea lights are generally termed the Liverpool leading lights ; being so situated that when the mariner brings them to appear as one light he is then in the proper direction for avoiding the sandbanks on taking the channel for Liverpool. The light from Bidston Hill is from oil with one reflector of silvered glass, which is no less than thirteen and a half feet diameter and its focus four feet. This immense reflector is illuminated by one large cotton wick which consumes one gallon of oil in four hours. This lighthouse is remarkable well taken care of — being in every respect clean and in good order. I cannot see any good reason for expending such a quantity of oil for one reflector as the same quantity would answer for thirty reflectors of twenty inches diameter, and I am confident that seven such reflectors would give an equal if not a superior light. Probably it may have been thought, as the light is wanted in the same direction with the rays of the Sea light, that therefore there ought to be but one reflector in each lighthouse. This, however, is proceeding upon a mistake, as seven or greater number of reflectors may be so set that their rays shall have an identical path.
The Sea light is situated near the beach and distant from Bidston Hill lighthouse three miles in a north-west direction. This lighthouse is a huge pile one hundred and thirty-five feet high, and like Bidston, has one reflector of silvered glass seven and a half feet diameter and thirteen inches focal distance. The Lake lights consist of a higher and lower lighthouse with one reflector of silver glass in each, three feet diameter, which are lighted with one wick or torch as in the two lighthouses last described, and are distant from the Sea light about three miles in a south-west direction. The high and low Lake lights are distant from each other about five hundred paces. They are erected for the use of vessels taking Lake Roads when the weather or other circumstances prevent them from getting up to Liverpool. When both lights are seen as one, vessels are then clear of the sandbanks and may stand in for the anchoring ground.
These four lighthouses have been erected by the Trade of Liverpool, under whose management they seem to be conducted with great propriety. At each lighthouse there is one keeper, and although both the Lake reflectors might be kept by one person, yet they prefer two with equal salaries as they are a check upon each other. Besides these, there is a fifth light (supported also by the Trade of Liverpool), namely, Lynas, in the Island of Anglesey, to direct vessels into Beaumaris Bay when put past Liverpool and the Lake roads, but this small light is in use only during the winter months. All of which are instances of a great commercial interest at the Port of Liverpool.
Stevenson was still learning his trade when he wrote this. He has exaggerated the height of Leasowe Lighthouse (which was recorded as 110 feet in contemporary surveys), and the width of Bidston’s reflector (12 feet according to Hutchinson himself, and confirmed by Joseph Cachin’s careful drawing in 1785). His remarks that Bidston would be better served by several smaller reflectors than one big one are correct, but Hutchinson had noted this himself many years earlier.