The Sydney Heads are a series of headlands that form the 2 km wide entrance to Sydney Harbour in Sydney, New South Wales, Australia. North Head and Quarantine Head are to the north; the Heads are contained within the Sydney Harbour National Park. Some features located on the heads are heritage-listed on the Australian National Heritage List. North Head is a headland south-east of the suburb of Manly, it is part of Sydney Harbour National Park. The headland is 3.85 square kilometres in area. The heritage-listed former Quarantine Station is located on North Head and is one of the few facilities that operated in each state of Australia from the mid-to-late-1800s until the 1980s. From 1828, Spring Cove, on the western side of North Head, was used to quarantine new arrivals to Sydney to minimise the spread of communicable diseases such as cholera and whooping cough, amongst other communicable diseases. In 1832, the whole area of North Head was set aside for a quarantine station. A permanent quarantine facility was set up in 1837 and continued to operate until 1984.
The buildings and site was added to the New South Wales State Heritage Register on 2 April 1999, the entire 277-hectare North Head site to the Australian National Heritage List on 12 May 2006, now forms part of the Sydney Harbour National Park. The site contains the remnants of Colonial New South Wales period buildings and equipment which were the best available means of combating major contagious diseases and hygiene-related conditions brought to the colony by ship. Soon after Federation the Commonwealth Government initiated a major building and infrastructure program which remains intact today; this program included similar, but smaller, quarantine stations around Australian ports, of which North Head is the only remaining example. This site dealt with major shipping-related epidemic outbreaks; as such, the quarantine complex represents one of the most complete collection of buildings, equipment and a setting showing how life was lived among the struggles and successes in public health of Australia's past.
After 1945 the requirements for quarantine changed to small air-travel family groups serving periods of observation due to a lack of required inoculations. To these groups the site provided a scenic haven in a rustic historic setting. Many of the inscriptions on the local sandstone outcrops record the names and reasons why previous colonial and latter occupants found themselves in such a place; the buildings remain much as they had been in a former age and provided an opportunity for air-travel'patients' to become acquainted with a unique collection of historic ephemera. In 1970 the Officer-in-Charge at the station, Herbert Lavaring, was awarded a Queens Birthday Honors Award for his efforts in keeping the historic site preserved while creating a practical, enriching environment for patients and the public to enjoy; the steam-powered laundry and fumigation autoclaves are a unique collection of industrial technology from the past. In 1975, Vietnamese refugees were housed there, in 1975 and 1976, Cyclone Tracy victims from Darwin, Northern Territory were housed there.
The station was closed in 1984 and the management of the site passed to the New South Wales National Parks and Wildlife Service. The facility is now a tourist facility and part of the former Quarantine Station may be leased for accommodation; the nearby Inner North Head clifftops have many inscriptions from the quarantine period as well as the remnants of 1940s coastal defenses in the form of two gun sites, a range-sighting post, four ammunition storage bunkers and a fortified outhouse. This location has been the site of erosion and geo-technical instability, it may be subject to natural rockfalls. From 1934, defence facilities were installed on the headland but were wound down in 1945. From 1953, there was a School of Artillery; the harbour reserve was established in 1979. The School of Artillery relocated to Puckapunyal army base in Victoria in 1998, but an artillery museum remains on the headland. In 2001, the site was passed to the Sydney Harbour Federation Trust for management. In 2010 the artillery collection was moved to the Army Museum Bandiana in Victoria.
There are still remains of the gun emplacements and artificial tunnels used by the army, many of which can be seen by the public or on guided tours. Located on North Head is the Australian Institute of Police Management, housed in a secure compound, the'Seamen's Quarters' of the quarantine station, a place where sailors with acquired STIs were treated and securely confined behind high sandstone walls. South Head is a headland, part of Sydney Harbour National Park, to the north of the suburb of Watsons Bay. A twenty-minute foreshore walk on the South Head Heritage Trail offers dramatic views of Middle Head, North Head and the Tasman Sea. Starting at the delightful Camp Cove Beach, an 1870s cobblestone path leads first to L
Quoins are masonry blocks at the corner of a wall. They exist in some cases to provide actual strength for a wall made with inferior stone or rubble and in other cases to make a feature of a corner, giving an impression of permanence and strength, reinforcing the onlooker's sense of a structure's presence. Stone quoins are used on brick buildings. Brick quoins may appear on brick buildings, extruding from the facing brickwork in such a way as to give the appearance of uniformly cut blocks of stone larger than the bricks. Where quoins are used for decoration and not for load-bearing, they may be made from a wider variety of materials beyond brick, stone or concrete, extending to timber, cement render or other stucco. In a traditional decorative use, large cuboid ashlar stone blocks or replicas are only used on the corners with their longest sides horizontally: the longest sides are laid to be on one wall plane the other that the corner forms; this forms a long-side, short-side alternate pattern, which by using the same size blocks alternates when the viewer passes the corner.
This can be called the horizontal quoining technique. A large and small cornerstones technique can be used, in this technique it is not uncommon for the alternate courses to be of different thickness, with the larger cornerstones thinner than the smaller cornerstones; the long and short quoining method instead places long stone blocks with their lengths oriented vertically, between smaller ones that are laid flat. This load bearing quoining is common in Anglo-Saxon buildings such as that of St Bene't's Church in Cambridge, England. Chisholm, Hugh, ed.. "Quoins". Encyclopædia Britannica. 22. Cambridge University Press
A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses and to serve as a navigational aid for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals, reefs and safe entries to harbors. Once used, the number of operational lighthouses has declined due to the expense of maintenance and use of electronic navigational systems. Before the development of defined ports, mariners were guided by fires built on hilltops. Since raising the fire would improve the visibility, placing the fire on a platform became a practice that led to the development of the lighthouse. In antiquity, the lighthouse functioned more as an entrance marker to ports than as a warning signal for reefs and promontories, unlike many modern lighthouses; the most famous lighthouse structure from antiquity was the Pharos of Alexandria, which collapsed following a series of earthquakes between 956 and 1323. The intact Tower of Hercules at A Coruña, Spain gives insight into ancient lighthouse construction.
Coins from Alexandria and Laodicea in Syria exist. The modern era of lighthouses began at the turn of the 18th century, as lighthouse construction boomed in lockstep with burgeoning levels of transatlantic commerce. Advances in structural engineering and new and efficient lighting equipment allowed for the creation of larger and more powerful lighthouses, including ones exposed to the sea; the function of lighthouses shifted toward the provision of a visible warning against shipping hazards, such as rocks or reefs. The Eddystone Rocks were a major shipwreck hazard for mariners sailing through the English Channel; the first lighthouse built there was an octagonal wooden structure, anchored by 12 iron stanchions secured in the rock, was built by Henry Winstanley from 1696 to 1698. His lighthouse was the first tower in the world to have been exposed to the open sea; the civil engineer, John Smeaton, rebuilt the lighthouse from 1756–59. He modelled the shape of his lighthouse on that of an oak tree.
He rediscovered and used "hydraulic lime," a form of concrete that will set under water used by the Romans, developed a technique of securing the granite blocks together using dovetail joints and marble dowels. The dovetailing feature served to improve the structural stability, although Smeaton had to taper the thickness of the tower towards the top, for which he curved the tower inwards on a gentle gradient; this profile had the added advantage of allowing some of the energy of the waves to dissipate on impact with the walls. His lighthouse influenced all subsequent engineers. One such influence was Robert Stevenson, himself a seminal figure in the development of lighthouse design and construction, his greatest achievement was the construction of the Bell Rock Lighthouse in 1810, one of the most impressive feats of engineering of the age. This structure was based upon Smeaton's design, but with several improved features, such as the incorporation of rotating lights, alternating between red and white.
Stevenson worked for the Northern Lighthouse Board for nearly fifty years during which time he designed and oversaw the construction and improvement of numerous lighthouses. He innovated in the choice of light sources, reflector design, the use of Fresnel lenses, in rotation and shuttering systems providing lighthouses with individual signatures allowing them to be identified by seafarers, he invented the movable jib and the balance crane as a necessary part for lighthouse construction. Alexander Mitchell designed the first screw-pile lighthouse – his lighthouse was built on piles that were screwed into the sandy or muddy seabed. Construction of his design began in 1838 at the mouth of the Thames and was known as the Maplin Sands lighthouse, first lit in 1841. Although its construction began the Wyre Light in Fleetwood, was the first to be lit; the source of illumination had been wood pyres or burning coal. The Argand lamp, invented in 1782 by the Swiss scientist, Aimé Argand, revolutionized lighthouse illumination with its steady smokeless flame.
Early models used ground glass, sometimes tinted around the wick. Models used a mantle of thorium dioxide suspended over the flame, creating a bright, steady light; the Argand lamp used whale oil, olive oil or other vegetable oil as fuel, supplied by a gravity feed from a reservoir mounted above the burner. The lamp was first produced by Matthew Boulton, in partnership with Argand, in 1784 and became the standard for lighthouses for over a century. South Foreland Lighthouse was the first tower to use an electric light in 1875; the lighthouse's carbon arc lamps were powered by a steam-driven magneto. John Richardson Wigham was the first to develop a system for gas illumination of lighthouses, his improved gas'crocus' burner at the Baily Lighthouse near Dublin was 13 times more powerful than the most brilliant light known. The vaporized oil burner was invented in 1901 by Arthur Kitson, improved by David Hood at Trinity House; the fuel was vaporized at high pressure and burned to heat the mantle, giving an output of over six times the luminosity of traditional oil lights.
The use of gas as illuminant became available with the invention of the Dalén light by Swedish engineer, Gustaf Dalén. He used Agamassan, a substrate, to absorb the gas allowing safe storage and hence
Mortimer William Lewis was an English-born architect and public servant who migrated to Australia and became Colonial Architect in the state of New South Wales from 1835 to 1849. Lewis was responsible for designing and overseeing many government buildings in Sydney and rural New South Wales, many of which are heritage listed. Lewis was born in Middlesex, London in 1796, to Thomas Arundel Lewis and Caroline Lewis At the age of nineteen, he started work as a surveyor and draughtsman in the London office of the Inspector General of Fortifications. In 1819, he married Elizabeth Clements, who bore him a daughter. Another son was to be born in Sydney, Australia. Lewis lived in the Eyre Estate near St Johns Wood. After eight years in private practice, Lewis received an appointment as assistant surveyor in the office of surveyor-general of New South Wales, he set sail with his family in 1829 and arrived in Sydney in March, 1830. Lewis arrived in Sydney via Hobart on 1 April 1830 as a free settler aboard the convict ship the Dunvegan Castle, which left Britain on 28 September 1829.
From 1830 Lewis worked in the office of surveyor-general of New South Wales under Sir Thomas Mitchell, during this time mapped the Great Dividing Range, 130 kilometres west of Sydney. Lewis was appointed to be the Town Surveyor. A long series of public works throughout New South Wales followed, including court houses, police stations and government buildings. Lewis supervised the construction of buildings designed by other architects, a notable example being Government House designed in England by Edward Blore. Lewis became the leading proponent in Australia of the Classical Revival style, in particular the Doric variation, although he did not design in this style. Lewis's post as Colonial Architect ended sourly after a public controversy concerning the construction of Sydney’s first museum. In the late 1840s he began designing Sydney's first museum, which would be absorbed into the present Australian Museum; the project experienced substantial cost overruns during construction and Lewis was criticised by both the press and politicians.
The museum was completed, but an official inquiry blamed Lewis and he was forced to resign as Colonial Architect in 1849, after twenty nine years in retirement, Lewis died of a kidney ailment in 1879. In 1835 Governor Bourke made suggestions within reports of that he had discovered an architect competent enough to satisfy his needs within the public works sector. Lewis' discovery to Bourke came at a time when there was desperate need of a Lunatic Asylum, adequate to deal with problem people within the colony. Lewis began work in 1836 and the Gladesville Asylum opened in 1838, his design had a simple traditional facade, symmetrical in elevation. The Ionic columns of the portico would have been one of the first examples of such ornate craftsmanship within Australia at this time, it was more common to see Doric columns with circular detailing at the capitals, requiring far less detail and craftsmanship than the ornate Ionic columns designed by Lewis. St John's Anglican Church of Camden, completed in 1849, is regarded as one of the finest examples of Gothic Revival architecture in Australia.
The church was constructed from local materials such as clay. The clay is known to produce bricks with a great variation in colour and the St. Johns church is no exception producing pink, russet and orange bricks. Lewis had an affinity with stucco at the time of construction and the bricks of the church were laid with the anticipation of a secondary finish which never occurred for unknown reasons; the laid bricks resulted in a richness in the facade, adding character and depth. Said to be one of Lewis’ most important works, the "erudite Greek Classic "Darlinghurst Courthouse was commenced in 1835 and completed in 1844. Lewis’ plan placed the court room in the centre, with a symmetrical arrangement of rooms for magistrates and court officials either side; the entry was through a pedimented porch framed with Doric columns, a direct imitation of an ancient Greek temple, except in this instance the Doric columns do not extend to the ground. It is said that the pattern in the sandstone columns was stopped at a height to avoid damage from passing traffic.
Darlinghurst Court was the first purposely designed courthouse to be built in NSW, with the general layout and form referenced for buildings of law in Australia for the next 60 years. These included Lewis’s Parramatta Courthouse, New South Wales, the Supreme Court, South Australia, by Richard Lambeth; the building was altered in 1886 by James Barnet to include major flanking court room additions. The extension facing Victoria Street, completed in 1963, was designed by the Government Architect's Office. Lewis acquired land in what was to become the beachside suburb of Bronte, started work on the sandstone bungalow which became Bronte House; the house was built with the intention of housing his family but Lewis was forced to sell mid-construction during the 1840s recession. The built property was purchased by Robert Lowe; the four square asymmetrical plan, including a bay and bow window, was typical of Lewis, except the external detailing, such as the romantic circular and hexagonal corner turrets, were assumed to have been altered to suit the new owners’ needs.
The building was sited in the substantial gardens of the irregular site. This picturesque style was not found in Australian Colonial architecture and was thought to be a t
A light characteristic is a graphic and text description of a navigational light sequence or colour displayed on a nautical chart or in a Light List with the chart symbol for a lighthouse, buoy or sea mark with a light on it. The graphic indicates how the real light may be identified when looking at its actual light output type or sequence. Different lights use different colours and light patterns, so mariners can identify which light they are seeing. While light characteristics can be described in prose, e.g. "Flashing white every three seconds", lists of lights and navigation chart annotations use abbreviations. The abbreviation notation is different from one light list to another, with dots added or removed, but it follows a pattern similar to the following. An abbreviation of the type of light, e.g. "Fl." for flashing, "F." for fixed. The color of the light, e.g. "W" for white, "G" for green, "R" for red, "Y" for yellow. If no color is given, a white light is implied; the cycle period, e.g. "10s" for ten seconds.
Additional parameters are sometimes added:The height of the light above the chart datum for height. E.g. 15m for 15 metres. The range in which the light is visible, e.g. "10M" for 10 nautical miles. An example of a complete light characteristic is "Gp Oc W 10s 15m 10M"; this indicates that the light is a group occulting light in which a group of three eclipses repeat every 10 seconds. A fixed light, abbreviated "F", is a steady light. A flashing light is a rhythmic light in which the total duration of the light in each period is shorter than the total duration of the darkness and in which the flashes of light are all of equal duration, it is most used for a single-flashing light which exhibits only single flashes which are repeated at regular intervals, in which case it is abbreviated as "Fl". It can be used with a group of flashes which are repeated, in which case the abbreviation is "Fl" or "Gr Fl", for a group of two flashes. Another possibility is a composite group, in which successive groups in the period have different numbers of flashes, e.g. "Fl." indicates a group of two flashes, followed by one flash.
A specific case sometimes used is. Such a light is sometimes denoted "long flashing" with the abbreviation "L. Fl". If the frequency of flashes is large the light is denoted as a "quick light", see below. An occulting light is a rhythmic light in which the duration of light in each period is longer than the total duration of darkness. In other words, it is the opposite to a flashing light where the total duration of darkness is longer than the duration of light, it has the appearance of flashing off, rather than flashing on. Like a flashing light, it can be used for a single occulting light that exhibits only a single period of darkness or the periods of darkness can be grouped and repeated at regular intervals, a group or a composite group; the term occulting is used because the effect was obtained by a mechanism periodically shading the light from view. An isophase light, abbreviated "Iso", is a light which has light periods of equal length; the prefix derives from the Greek iso- meaning "same".
A quick light, abbreviated "Q", is a special case of a flashing light with a large frequency. If the sequence of flashes is interrupted by repeated eclipses of constant and long duration, the light is denoted "interrupted quick", abbreviated "I. Q". Group notation similar to flashing and occulting lights is sometimes used, e.g. Q. Another distinction sometimes made is between quick quick and ultra quick; this can be combined with notations for interruptions, e.g. I. U. Q for interrupted ultra quick, or grouping, e.g. V. Q for a quick group of nine flashes. Quick characteristics can be followed by other characteristics, e.g. VQ LFl for a quick group of six flashes, followed by a long flash. A Morse code light is light in which appearances of light of two different durations are grouped to represent a character or characters in the Morse Code. For example, "Mo" is a light in which in each period light is shown for a short period followed by a long period, the Morse Code for "A". A fixed and flashing light, abbreviated "F. Fl", is a light in which a fixed low intensity light is combined with a flashing high intensity light.
An alternating light, abbreviated "Al", is a light. For example, "Al WG" shows green lights alternately. Lighthouse Pilotage Signal lamp U. S. ATON light characteristic terms illustrated
A hip roof, hip-roof or hipped roof, is a type of roof where all sides slope downwards to the walls with a gentle slope. Thus a hipped roof house has other vertical sides to the roof. A square hip roof is shaped like a pyramid. Hip roofs on houses could have two trapezoidal ones. A hip roof on a rectangular plan has four faces, they are always at the same pitch or slope, which makes them symmetrical about the centerlines. Hip roofs have a consistent level fascia, meaning that a gutter can be fitted all around. Hip roofs have dormer slanted sides. Hip roofs are more difficult to construct than a gabled roof, requiring more complex systems of rafters or trusses. Hip roofs can be constructed on a wide variety of plan shapes; each ridge is central over the rectangle of the building below it. The triangular faces of the roof are called the hip ends, they are bounded by the hips themselves; the "hips" and hip rafters sit on an external corner of the rise to the ridge. Where the building has an internal corner, a valley makes the join between the sloping surfaces.
They have the advantage of giving a solid appearance to a structure. The roof pitch may vary. In modern domestic architecture, hip roofs are seen in bungalows and cottages, have been integral to styles such as the American Foursquare. However, the hip roof has been used in many different styles of architecture and in a wide array of structures. A hip roof is self-bracing. Hip roofs are thus much better suited for hurricane regions than gable roofs. Hip roofs have no large, flat, or slab-sided ends to catch wind and are inherently much more stable than gable roofs. However, for a hurricane region, the roof has to be steep-sloped; when wind flows over a shallow sloped hip roof, the roof can behave like an airplane wing. Lift is created on the leeward side; the flatter the roof, the more this will happen. A steeper pitched hip roof tends to cause the wind to stall as it goes over the roof, breaking up the effect. If the roof slopes are less than 35 degrees from horizontal, the roof will be subject to uplift.
Greater than 35 degrees, not only does wind blowing over it encounter a stalling effect, but the roof is held down on the wall plate by the wind pressure. A possible disadvantage of a hip roof, compared with a gable roof on the same plan, is that there is less room inside the roof space. A mansard roof is a variation on a hip roof, with two different roof angles, the lower one much steeper than the upper. A tented roof is a type of polygonal hipped roof with steeply pitched slopes rising to a peak or intersection. Another variation is the gablet or Dutch gable roof; this type simplifies the construction of the roof. A half-hip, clipped-gable or jerkin head roof has a gable, but the upper point of the gable is replaced by a small hip, squaring off the top of the gable; the lower edge of the half-hip may have a gutter which leads back on to the remainder of the roof on one or both sides. Both the gablet roof and the half-hipped roof are intermediate between the gabled and hipped types: the gablet roof has a gable above a hip, while a half-hipped roof has a hip above a gable.
Half-hipped roofs are common in Denmark, Germany and in Austria and Slovenia. They are typical of traditional timber frame buildings in the Wealden area of South East England. Half hip roofs are sometimes referred to as "Dutch hip", but this term is confused with "Dutch gable". A hip roof on a square structure found topping gazebos and other pavilion structures known as a pyramid roof. A pointed roof seen on a tower, oriented so that it has four gable ends. See Church of St Mary the Blessed Virgin, Speyer Cathedral, or Limburg Cathedral. Domestic roof construction Finial, or hip-knob Hip Roof - Encyclopædia Britannica Hip Roof layout Roofs and roofing Hip roof geometry. Google SketchUp 3D model where each roof member and bevel can be interrogated
Ashlar is finely dressed stone, either an individual stone, worked until squared or the structure built of it. Ashlar is the finest stone masonry unit cuboid, mentioned by Vitruvius as opus isodomum, or less trapezoidal. Cut "on all faces adjacent to those of other stones", ashlar is capable of thin joints between blocks, the visible face of the stone may be quarry-faced or feature a variety of treatments: tooled, smoothly polished or rendered with another material for decorative effect. One such decorative treatment consists of small grooves achieved by the application of a metal comb. Used only on softer stone ashlar, this decoration is known as mason's drag. Ashlar is in contrast to rubble masonry, which employs irregularly shaped stones, sometimes minimally worked or selected for similar size, or both. Ashlar is related but distinct from other stone masonry, finely dressed but not quadrilateral, such as curvilinear and polygonal masonry. Ashlar may be coursed, which involves lengthy horizontals layers of stone blocks laid in parallel, therefore with continuous horizontal joints.
Ashlar may be random, which involves stone blocks laid with deliberately discontinuous courses and therefore discontinuous joints both vertically and horizontally. In either case, it uses a joining material such as mortar to bind the blocks together, although dry ashlar construction, metal ties, other methods of assembly have been used; the dry ashlar of Inca architecture in Cusco and Machu Picchu is fine and famous. The word is attested in Middle English and derives from the Old French aisselier, from the Latin axilla, a diminutive of axis, meaning "plank". "Clene hewen ashler" occurs in medieval documents. Ashlar blocks have been used in the construction of many buildings as an alternative to brick or other materials. In classical architecture, ashlar wall surfaces were contrasted with rustication; the term is used to describe the dressed stone work of prehistoric Greece and Crete, although the dressed blocks are much larger than modern ashlar. For example, the tholos tombs of Bronze Age Mycenae use ashlar masonry in the construction of the so-called "beehive" dome.
This dome consists of finely cut ashlar blocks that decrease in size and terminate in a central capstone. These domes are constructed using the corbel arch. Ashlar masonry was heavily used in the construction of palace facades on Crete, including Knossos and Phaistos; these constructions date to the MM III-LM Ib period, ca. 1700–1450 BC. In modern European masonry the blocks are about 35 centimetres in height; when shorter than 30 centimetres, they are called small ashlar. In some Masonic groupings, which such societies term jurisdictions, ashlars are used as a symbolic metaphor for how one's personal development relates to the tenets of their lodge; as described in the explanation of the First Degree Tracing Board, in Emulation and other Masonic rituals the rough ashlar is a stone as taken directly from the quarry, allegorically represents the Freemason prior to his initiation. Ablaq Dimension stone Opus quadratum Rustication Stone cladding Stone veneer