Lines of Sight

The history of Bidston Hill is all about line of sight communications. From Bidston Hill, one can see (and be seen) for many miles in all directions.

Fire Beacons have been deployed on Bidston Hill for centuries. We know they were prepared as part of an early-warning system during the Spanish Armada and again during the Napoleonic Wars. They may have been used even earlier.

In navigation, the Windmill on Bidston Hill was used as a “day mark” long before Wirral’s first lighthouses were built in 1763. This is why many early sea charts of Liverpool Bay took pains to mark the location of Bidston Windmill.

The Bidston Signals comprised more than a hundred “lofty flagstaffs” running along the ridge of Bidston Hill. Their purpose was to give the port of Liverpool notice of arriving ships.

Bidstone Lighthouse and Signal

Bidstone Lighthouse and Signals, by Henry F. James, c. 1807. The original is in the collection of the Williamson Art Gallery.

Lighthouses, too, depend on line of sight. To be useful, they must be seen. Liverpool’s first lighthouses were built in Wirral in 1763. These were navigational aids, not warning lights. By setting a course with the two lights straight ahead, mariners avoided the treacherous sand banks of Liverpool Bay. The two Sea Lights, near Leasowe, marked the safe passage through the Horse Channel, and the two Lake Lights marked the way into Hoyle Lake. This was an early (but not the earliest) use of leading lights in navigation.

The first Bidston Lighthouse was built in 1771, near the Signals Station. It was needed because the lower Sea Light had been overwhelmed by storms. Bidston Lighthouse became the upper Sea Light, and Leasowe Lighthouse, still standing today, became the lower Sea Light. Being 2.3 miles further inland, the new lighthouse depended on a breakthrough in lighthouse optics, which came in the form of William Hutchinson’s invention of the parabolic reflector.

Bidston Lighthouse by Robert Salmon, Oil on Canvas, 1825. Courtesy of National Museums Liverpool.

Bidston Lighthouse by Robert Salmon, Oil on Canvas, 1825. Courtesy of National Museums Liverpool.

In 1826, the Liverpool to Holyhead telegraph was set up. This was an optical telegraph, based on a new semaphore system devised by Lieutenant Barnard Lindsay Watson. It comprised a chain of semaphore stations at Liverpool, Bidston Hill, Hilbre Island, Voel Nant, Foryd, Llysfaen, Great Ormes Head, Puffin Island, Point Lynas, Carreglwyd, and Holyhead, a distance of 72 miles.  It was capable of relaying a typical message from Holyhead to Liverpool in a few minutes, and a very short message in less than a minute. This was the first telegraph in Britain to carry commercial and private correspondence. Watson’s code was a numeric one: each station in the 1826 telegraph had a massive semaphore mast about 50 feet tall, each pole had three pairs of movable arms, and each pair of arms could signal a single digit. The 1841 telegraph had a two masts each with two pairs of arms, and a larger vocabulary of 10,000 words.

All of these systems were made obsolete by the inexorable march of technology. Last to arrive and first to go was the optical telegraph,  which was superseded when the electric telegraph linking Liverpool to Holyhead was finally completed in 1861, the first cables having been laid in 1858. Next to go were the signal flags. The Sea Lights were superseded by navigational buoys, which had the virtue of being moveable. By 1908, when the Lower Sea Light at Leasowe was extinguished, the sandbanks had shifted to such an extent that the Horse and Rock Channels were barely navigable, and the Sea Lights no longer provided a useful leading line. The Upper Sea Light on Bidston Hill shone alone for another five years, until sunrise on 9th October, 1913.

Radio is another form of communications that depends on line of sight. The principle of propagation of electromagnetic waves was discovered by James Clerk Maxwell in 1873, the same year that the present Bidston Lighthouse was completed. Marconi won an important patent in 1896, and built the first radio station on the Isle of Wight in 1897. Then it really took off.

At Bidston Lighthouse (and Bidston Observatory), radio antennae of all kinds have been installed at one time or another. Mersey Docks ordered a set of “Marconi Apparatus” for Bidston Lighthouse as early as 1908, but the Marconi Company failed to deliver, and the order was withdrawn. An antenna, probably marine, is still attached to the north face of the lighthouse tower. Amateur radio enthusiasts, notably the Wirral Amateur Radio Society, still operate from Bidston Lighthouse on annual International Lighthouse and Lightship Weekends, and other special occasions. Our webcam is brought to you over a line-of-sight wireless network. In 2014, Wirral Radio 92.1 FM moved their transmitter to Bidston Lighthouse.

Line-of-sight communications are as much a part of the future of Bidston Lighthouse as its past.

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2 thoughts on “Lines of Sight

  1. admin Post author

    Because the original 1762 Act of Parliament specifically empowered the Port of Liverpool to build lighthouses within one mile of the sea, it has sometimes been assumed that building a lighthouse on Bidston Hill must have required a new Act. I have acquired a little volume, once in the library of the Mersey Docks and Harbour Board, containing what was presumably meant to be a complete set of the Acts of Parliament pertaining to the Port of Liverpool. This volume contains no additional Act covering the construction of Bidston Lighthouse.

    On closer inspection of the wording of the 1762 Act, a new Act was probably not required in order to build a lighthouse on Bidston Hill. In the 1762 Act, the restriction to one mile from the sea was actually not a restriction, but a condition: the Port of Liverpool had to build at least four lighthouses within a mile of the sea before it could start charging light dues to recover the construction costs (which explains why they lost so little time in making the Sea Lights and Lake Lights operational). The 1762 Act also granted to the Port of Liverpool additional powers to acquire land, build roads, and erect buildings to aid navigation, and no restriction was placed on their location.

    I have therefore updated the post to remove the sentence: “This required a new Act of Parliament, because the previous Act only allowed the Port of Liverpool to construct lighthouses within one mile of the shore, and Bidston Hill was more than two miles from the sea.”

    Reply
  2. admin Post author

    I have updated the section on Radio to mention the FM radio transmitter of 2014, and the “Marconi apparatus” of 1908. One reference for the Marconi Apparatus is “The Engineer” 31 July 1908, which says, on page 117:

    “The Mersey Docks and Harbour Board have decided to arrange for the hire of two sets of Marconi apparatus — one for the North-West Lightship and the other for the Bidstone Lighthouse and Telegraph Station. The hire is to be for one year certain, subject to three months’ notice at the expiration of that period.”

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