Bidston Lighthouse was visible from both. The other, more likely, is Liverpool docks. One is at the north coast of the Wirral peninsula, somewhere along Mockbeggar Wharf. 55 ft according to BurdettвЂ™s Chart of 1771 ), it is not clear whether these include the weather vane, chimney or flagpole erected atop the tower.ДЄs Bidston Lighthouse is some two miles from the sea, the location of the high water mark to which the elevation is referenced is not immediately obvious. And while some contemporary descriptions give a height for the tower (e.g. So the elevations at the bases of the 17 towers could have differed by a metre or two. The new lighthouse was built a few yards or so to the north of the original, and there was extensive work on the foundations. This is difficult to check, as the original Bidston Lighthouse was replaced in 1873. The elevation is the height of the flame, and is given as 228 feet above high water. 23 nautical miles is 26.5 international miles or 42.6 kilometres, near enough. In the use of coloured lights this range is given according to their presumed power. But in the case of the principal lights this but imperfectly represents their range, as they could be seen at any distance attainable by increased elevation. This gives the minimum distance to which the light can be seen, in clear weather, from a height of 10 feet above the sea level. The height of the lighthouse itself, from base to summit, is given sometimes in the third column. This gives the height of the flame above the highest tide level, consequently it is its minimum height, and is increased by the tidal range of the place. To avoid any ambiguity, I quote FindlayвЂ™s explanations of columns 5 and 6 verbatim: The black circle in column 4 denotes a catoptric reflector.

Bidston is written in block capitals because it is a principal light. Findlay, 1861.ДЇindlay explains the meaning of each column on page 32. Extract from вЂњLighthouses of the WorldвЂќ, Alexander G. The entry for Bidston is on page 39.ДЇigure 1. LetвЂ™s start with FindlayвЂ™s Lighthouses of the World. I should disclose at this point that I do not, and never have, subscribed to any Flat Earth theory. You can bear with me as I try to make sense of it, or you can read this instead. One thing is certain those who seek only anomalous lighthouses will never find light. By now, however, some of RowbothamвЂ™s lighthouses presumably have been closed, torn down, or destroyed by the elements. Perhaps, for those lighthouses still operating, new observations would not confirm the reported anomalies. Perhaps the reported observations were made under unusual conditions. Schadewald concluded:ДЄnd what about RowbothamвЂ™s anomalous lighthouses? Beats me. Bresher before him, vigorously refuted RowbothamвЂ™s arguments, but could not explain the anomalies in Lighthouses of the World. Schadewald picked up the story in his 1992 article Looking for Lighthouses. Deducting 4 miles for the height of the observer, squaring the remaining 23 miles and multiplying that product by 8 inches we have a downward curvature of 352 feet from this deduct the altitude of the light, 228 feet, and there remains 124 feet as the distance which the light should be below the horizon !

Bidston Lighthouse was one of his chief examples:Д«y the same authority, at page 39, the Bidston Hill Lighthouse, near Liverpool, is 228 feet above high water, one bright fixed light, visible 23 nautical or very nearly 27 statute miles. Findlay (1861-2) to support his thesis that the earth was flat. He drew on, amongst other things, information published in Lighthouses of the World by Alexander G. Writing under the pseudonym вЂњParallaxвЂќ, Rowbotham published Zetetic Astronomy: Earth Not a Globe in 1865. In the nineteenth century, a fellow called Samuel Birley Rowbotham promoted a flat earth system which he called Zetetic Astronomy.

What is zetetic astronomy