Round Island Lighthouse ( "the hump lighthouse"), in the

Isles of Scilly The Isles of Scilly ( ; ) are a small archipelago off the southwestern tip of Cornwall, England. One of the islands, St Agnes, Isles of Scilly, St Agnes, is over farther south than the most southerly point of the Great Britain, British mainla ...

was designed by William Tregarthen Douglass for

Trinity House The Corporation of Trinity House of Deptford Strond, also known as Trinity House (and formally as The Master, Wardens and Assistants of the Guild Fraternity or Brotherhood of the most glorious and undivided Trinity and of St Clement in the ...

and completed in 1887. At the time of building it was one of three lights in the Isles of Scilly, the others being the

Bishop Rock The Bishop Rock () is a skerry off the Great Britain, British coast in the northern Atlantic Ocean known for its lighthouse. It is in the westernmost part of the Isles of Scilly, an archipelago off the southwestern tip of the Cornwall, Cornish ...

and St Agnes lighthouse. The light was modernised in 1966, automated in 1987 and the island designated as a

Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain, or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland, is a conservation designation denoting a protected area in the United Kingdom and Isle ...

(SSSI) in 1995. It is now managed by the

Isles of Scilly Wildlife Trust The Isles of Scilly Wildlife Trust, formed in 1985, is a Wildlife Trust covering the Isles of Scilly, a group of islands off the coast of Cornwall. It became the 46th member of The Wildlife Trusts in 2001 and is dedicated to ensuring that the a ...

, and except for the maintenance of the Grade II listed lighthouse, landing is not allowed.

History

cairn A cairn is a human-made pile (or stack) of stones raised for a purpose, usually as a marker or as a burial mound. The word ''cairn'' comes from the (plural ). Cairns have been and are used for a broad variety of purposes. In prehistory, t ...

or burial chamber was destroyed when the lighthouse was built. Cairns on the Isles of Scilly date back to the

Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...

and at that time Round Island was probably a peninsula on the northern shore of the main island in the Isles of Scilly. The

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

ashlar Ashlar () is a cut and dressed rock (geology), stone, worked using a chisel to achieve a specific form, typically rectangular in shape. The term can also refer to a structure built from such stones. Ashlar is the finest stone masonry unit, a ...

, tall tower was designed by William Tregarthen Douglass, chief engineer for the

Commissioners of Irish Lights The Commissioners of Irish Lights (), often shortened to Irish Lights or CIL, is the body that serves as the general lighthouse authority for Northern Ireland and the Republic of Ireland and their adjacent seas and islands. As the lighthouse a ...

, and is built on a tall mass of Hercynian granite. At the time of building the only access was up a flight of steps cut out of the rock on the south side of the island. Supplies were taken up the rock face by an aerial hoist: a wire rope strung between the island and an adjacent islet was rigged with a traveller, which enabled goods to be winched up from delivery boats below. Within the walls of the lighthouse the keepers tended a small vegetable garden, for which the soil was transported to the island. The light was first lit on 12 November 1887 and has a

focal plane In Gaussian optics, the cardinal points consist of three pairs of points located on the optical axis of a rotationally symmetric, focal, optical system. These are the '' focal points'', the principal points, and the nodal points; there are two ...

of 180 feet. It originally had an enormous biform hyperradial optic high and weighing more than 8 tons. It was built by Chance Brothers & Co of Birmingham and, said at the time, to be ″'' .... in relation both to size and character .... the most remarkable works of their kind hitherto achieved.''″ A similar optic had been installed in the nearby Bishop Rock Lighthouse the previous year. In order to differentiate the Round Island light from Bishop's Rock it was made to show a single red flash every 30 seconds (whereas Bishop's Rock gave a double white flash). At the centre of the optic was a pair of ten-wick Douglass oil burners (larger than the eight-wick burners installed at Bishop Rock); these unusually large lamps helped compensate for the reduced intensity caused by the light passing through red-tinted glass. Mineral oil for the lamps was stored in tanks, located at the south end of the island alongside the aerial host. The optic was turned by a small

air engine A pneumatic motor (air motor), or compressed-air engine, is a type of motor which does mechanical work by expanding compressed air. Pneumatic motors generally convert the compressed-air energy to mechanical work through either linear or rotary m ...

placed in the pedestal; compressed air was provided from a set of compressors and tanks located in a separate engine house (a detached building to the south of the tower), powered by a pair of Davey 'Safety' Engines. In 1912 the lighthouse was provided with a fog siren, sounded through a pair of large red-painted

Rayleigh Rayleigh may refer to: Science *Rayleigh scattering *Rayleigh–Jeans law *Rayleigh waves *Rayleigh (unit), a unit of photon flux named after the 4th Baron Rayleigh *Rayl, rayl or Rayleigh, two units of specific acoustic impedance and characte ...

Trumpets mounted on the roof of a fog horn house, adjacent to the lighthouse itself on the north side. It sounded four blasts every two minutes. The engine house was upgraded and equipped with a pair of 22 hp Hornsby oil engines which drove the compressor. These remained in service until the late 1960s, when they were replaced with diesel engines. Britain's first wireless beacon for navigation, designed for Trinity House by the

Marconi Company The Marconi Company was a British telecommunications and engineering company founded by Italian inventor Guglielmo Marconi in 1897 which was a pioneer of wireless long distance communication and mass media broadcasting, eventually becoming on ...

, was established at Round Island Lighthouse in 1927, (following the trial run of an experimental system there two years earlier). The installation consisted of a 'multi-wire inverted L type aerial' strung between the lighthouse gallery and a steel lattice tower. It automatically transmitted a repeated cycle, including the station's unique call sign ('GGG' in

Morse code Morse code is a telecommunications method which Character encoding, encodes Written language, text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code i ...

), for nine minutes every half hour (or continuously in foggy weather). Similar systems were subsequently installed at lighthouses and other locations around the coast of Britain. Later, in 1961, a more powerful radio beacon set was installed on the island. In 1966 the light was electrified. The old hyperradial optic was replaced by a flat vertical panel with rows of

sealed beam A parabolic aluminized reflector lamp (PAR lamp or simply PAR) is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. It produces a highly directional beam. Usage includes theatrical lighti ...

lamps, each covered by a red shade, which was mounted on an AGA revolving gearless pedestal. A helicopter pad was built on the rock alongside the lighthouse in 1969, but boat deliveries also continued; the aerial hoist was upgraded in 1972. The optic was replaced again in 1987 when the light was automated and its colour changed from red to white, emitting one white flash every ten seconds; it had an intensity of 340,000

candela The candela (symbol: cd) is the unit of luminous intensity in the International System of Units (SI). It measures luminous power per unit solid angle emitted by a light source in a particular direction. Luminous intensity is analogous to radi ...

and a range of . Prior to automation, the siren was replaced with an electric nautophone signal. In 2002-3 the lighthouse was converted to solar power, with

photovoltaic cells A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by means of the photovoltaic effect.

replacing the erstwhile constantly running diesel alternator sets as the power source for the light and fog signal. The lamp was upgraded to an

LED A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresp ...

in 2025. The lighthouse continues to display one white flash every ten seconds; the revolving drum optic has an intensity of 42,945

and a range of . The

fog signal A foghorn or fog signal is a device that uses sound to warn vehicles of navigational hazards such as rocky coastlines, or boats of the presence of other vessels, in foggy conditions. The term is most often used in relation to marine transport. ...

sounds four blasts every minute.

Wildlife and ecology

Round Island was designated a Site of Special Scientific Interest in 1995 as part of the Pentle Bay, Merrick and Round Islands SSSI. The island is important for its breeding seabirds, especially the European storm–petrel ('' Hydrobates pelagicus''). Breeding storm–petrels were unrecorded on Round Island for many years, until one of the lighthouse keepers, mystified by the nightly appearance of black feathers in the living quarters, decided to keep some. When the identity of the bird was discovered, the cat was banished. The Seabird 2000 survey counted 183 occupied nests and a follow–up survey in 2006 found 251 occupied nests on the island; the second highest total in the Isles of Scilly. The seabird survey in 2000 also recorded 34 occupied nests of

Manx shearwater The Manx shearwater (''Puffinus puffinus'') is a medium-sized shearwater in the seabird family Procellariidae. The scientific name of this species records a name shift: Manx shearwaters were called Manks puffins in the 17th century. Puffin is an ...

(''Puffinus puffinus'').

Puffins Puffins are any of three species of small alcids (auks) in the bird genus ''Fratercula''. These are pelagic seabirds that feed primarily by diving in the water. They breed in large colonies on coastal cliffs or offshore islands, nesting in crev ...

(''Fratercula arctica'') were first recorded as breeding on Round Island in 1850 by Issac North and during the building of the lighthouse it was said that ″''They (puffins) were extremely tame and used to walk in and out of the kitchen of the workmen who built the tower. This tameness, and the edibility of their eggs, proved their undoing, for none survive now''″. Brown rats (''

Rattus norvegicus ''Rattus'' is a genus of muroid rodents, all typically called rats. However, the term rat can also be applied to rodent species outside of this genus. Species and description The best-known ''Rattus'' species are the black rat (''R. rattus' ...

'') were discovered on the island in January 2022 and volunteers landed on the island thirteen times to set up bait stations, which removed the rats before the return of Manx shearwater and European storm petrel in April. If the rats were not removed they would have ate the chicks. On the last couple of trips to remove the rats, teeth marks of the Scilly shrew (''Crocidura suaveolens'') were found on non-toxic chocolate wax. With the removal of rats the population should also recover. Permission is needed from Trinity House to land on the island and only two botanists are known to have visited. The first, J. E. Lousley, in 1957, only recorded the invasive Hottentot fig (''

Carpobrotus edulis ''Carpobrotus edulis'' is a creeping plant with succulent leaves in the genus '' Carpobrotus'', native to South Africa. Its common names include hottentot-fig, sour fig, ice plant, highway ice plant, or vygie. Description ''Carpobrotus eduli ...

''). Thirty years later, in 1987, Rosemary Parslow found much of the ground between the buildings and the cliff edge was covered in a carpet of purple dewplant (''

Disphyma crassifolium ''Disphyma crassifolium'', commonly known as round-leaved pigface or salty fingers is a species of flowering plant in the family Aizoaceae native to Australia and the Cape Provinces of South Africa. It is a prostrate, succulent annual shrub or s ...

'') and Hottentot fig. She also recorded a small number of the expected coastal species. They were sea spleenwort (''

Asplenium marinum ''Asplenium marinum'' is a fern known as the sea spleenwort because of its preference for maritime habitats. Located around the coasts of Europe from Italy in the South to Norway in the North, its most Southern distribution extends to the Norther ...

''), bird's–foot trefoil (''

Lotus corniculatus ''Lotus corniculatus'' is a flowering plant in the pea family Fabaceae. Common names include common bird's-foot trefoil, eggs and bacon, birdsfoot deervetch, and just bird's-foot trefoil (a name also often applied to other ''Lotus'' spp.). It ha ...

''), spear–leaved orache (''

Atriplex prostrata ''Atriplex prostrata'', called the spear-leaved orache, hastate orache, thin-leaf orache, triangle orache, and fat hen, is a widespread species of flowering plant in the saltbush genus ''Atriplex ''Atriplex'' () is a plant genus of about 250 ...

''), sea beet ('' Beta vulgaris subsp. maritima''), rock sea spurrey (''

Spergularia rupicola ''Spergularia rupicola'' is a species of flowering plant belonging to the family Caryophyllaceae. It is native to Western Europe. References rupicola ''Rupicola'' was a small genus of flowering plants in the family Ericaceae. The speci ...

''), thrift (''

Armeria maritima ''Armeria maritima'', the thrift, sea thrift or sea pink, is a species of flowering plant in the family Plumbaginaceae. It is a compact evergreen perennial which grows in low clumps and sends up long stems that support globes of bright pink flow ...

'') and tree mallow (''

Lavatera arborea ''Malva arborea'' (previously known as ''Lavatera arborea'', or, more recently as ''Malva eriocalyx''), the tree mallow, is a species of mallow native to the coasts of western Europe and the Mediterranean region, from Ireland and Britain south t ...

''). Gusts of winds can be ferocious such as in 1954 when there was continuous gales from 29 November to 16 December. Wind velocities of 177 km/h ( 110 mph) were recorded at the Bishop Rock where seas raced past the window, and on Round Island the

wind gauge Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ...

was destroyed at 177 km/h.

Gallery

File:Round Island with boat Isles of Scilly by Kernow Skies.jpg File:Round Island Isles of Scilly by Kernow Skies.jpg

References

External links

Round Island Lighthouse at Trinity House

Isles of Scilly Wildlife Trust
* online information Trinity House. {{DEFAULTSORT:Round Island Light, Isles Of Scilly Grade II listed lighthouses Lighthouses completed in 1887 Lighthouses in the Isles of Scilly Sites of Special Scientific Interest in the Isles of Scilly Sites of Special Scientific Interest notified in 1995 Uninhabited islands of the Isles of Scilly

History

Wildlife and ecology

Gallery

See also

References

External links