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John Brown (builder)
John Brown (1809–1876) was a Canadian builder of Scottish origin. Brown began his career as a stonemason's apprentice in Glasgow. At 23 he emigrated to the United States, to upstate New York. By 1838 he had moved again, this time to Thorold, Ontario, where he was to spend the remainder of his career. Brown's first government project was the construction of the Gull Island Lighthouse in Lake Erie between 1846 and 1848. Subsequently, he was retained to build seven additional lightstations in Ontario, including one in Burlington, Ontario. Brown is best remembered for building Ontario's Imperial Towers, six nearly identical light stations (tower and keeper's dwelling) made of cut stone, and not brick, metal, wood or concrete that was common in the 1850s. All were on Lake Huron or Georgian Bay. Initially, eleven were planned but only six were built, between 1855 and 1859. (The projects cancelled were to be at White Fish Island, Mississagi Strait, Isle St. Joseph, Clapperton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Architect
An architect is a person who plans, designs and oversees the construction of buildings. To practice architecture means to provide services in connection with the design of buildings and the space within the site surrounding the buildings that have human occupancy or use as their principal purpose. Etymologically, the term architect derives from the Latin ''architectus'', which derives from the Greek (''arkhi-'', chief + ''tekton'', builder), i.e., chief builder. The professional requirements for architects vary from place to place. An architect's decisions affect public safety, and thus the architect must undergo specialized training consisting of advanced education and a ''practicum'' (or internship) for practical experience to earn a Occupational licensing, license to practice architecture. Practical, technical, and academic requirements for becoming an architect vary by jurisdiction, though the formal study of architecture in academic institutions has played a pivotal role in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cove Island Light
The Cove Island Light, at Gig Point on the island, is located in Fathom Five National Marine Park, but is not part of the Park. It is situated on the Bruce Peninsula, Ontario Canada. It has been a navigational aid in the narrow channel between Lake Huron and Georgian Bay since 30 October 1858. It was the first of six stone Imperial Towers to be completed; all were illuminated by 1859. Most other lighthouses of the era were built of brick, wood, iron or concrete. The six were built at a time when commercial shipping traffic was increasing on the Great Lakes between Canada and the U.S. because of new trade agreements and the opening of the Sault Ste. Marie Canal locks in 1855. The settlement of the Bruce Peninsula was also well underway by then, making the lighthouses even more useful. They acted as navigational aids for the boats and ships on Lake Huron and Georgian Bay. All are currently operating as automated lights. The Tower, Cove Island, Ontario, was formally registered on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitewash
Whitewash, or calcimine, kalsomine, calsomine, or lime paint is a type of paint made from slaked lime ( calcium hydroxide, Ca(OH)2) or chalk calcium carbonate, (CaCO3), sometimes known as "whiting". Various other additives are sometimes used. Use as paint Whitewash cures through a reaction with carbon dioxide in the atmosphere to form calcium carbonate in the form of calcite, a type of reaction generally known as carbonation or by the more specific term, carbonatation. It is usually applied to exteriors; however, it has been traditionally used in interiors of food preparation areas, particularly rural dairies, because of its mildly antibacterial properties. Whitewash can be tinted for decorative use and is sometimes painted inside structures such as the hallways of apartment buildings. However it can rub off onto clothing to a small degree. In Britain and Ireland, whitewash was used historically in interiors and exteriors of workers' cottages and still retains something o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cast Iron
Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing. Carbon (C), ranging from 1.8 to 4 wt%, and silicon (Si), 1–3 wt%, are the main alloying elements of cast iron. Iron alloys with lower carbon content are known as steel. Cast iron tends to be brittle, except for malleable cast irons. With its relatively low melting point, good fluidity, castability, excellent machinability, resistance to deformation and wear resistance, cast irons have become an engineering material with a wide range of applications and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of the molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Soda–lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term ''glass'', in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and eyeglasses, are so commonly made of silicate-based glass that they are simply called by the name of the material. Despite bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, opacity (optics), opacity, and lustre (mineralogy), luster, but may have properties that differ from those of the pure metals, such as increased strength or hardness. In some cases, an alloy may reduce the overall cost of the material while preserving important properties. In other cases, the mixture imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Alloys are defined by a metallic bonding character. The alloy constituents are usually measured by mass percentage for practical applications, and in Atomic ratio, atomic fraction for basic science studies. Alloys are usually classified as substitutional or interstitial alloys, depending on the atomic arrangement that forms the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite () is a coarse-grained (phaneritic) 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 cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) contain almost no dark minerals. Granite is nearly alway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite, a closely related rock, which contains a high percentage of the mineral dolomite, . ''Magnesian limestone'' is an obsolete and poorly-defined term used variously for dolomite, for limes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cone (geometry)
A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines connecting a common point, the apex, to all of the points on a base that is in a plane that does not contain the apex. Depending on the author, the base may be restricted to be a circle, any one-dimensional quadratic form in the plane, any closed one-dimensional figure, or any of the above plus all the enclosed points. If the enclosed points are included in the base, the cone is a solid object; otherwise it is a two-dimensional object in three-dimensional space. In the case of a solid object, the boundary formed by these lines or partial lines is called the ''lateral surface''; if the lateral surface is unbounded, it is a conical surface. In the case of line segments, the cone does not extend beyond the base, while in the case of half-lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point Clark Lighthouse
Point Clark Lighthouse is located on in a beach community, Point Clark, Ontario, near a point that protrudes into Lake Huron. Built between 1855 and 1859 under the instructions of the Board of Works, Canada West, it is one of the few on the Great Lakes to be made primarily from stone. It is one of the Imperial Towers, a group of six nearly identical towers built by contractor John Brown for the "Province of Canada" (Canadian government) on Lake Huron and Georgian Bay, all completed by 1859. The location for the Point Clark lighthouse was selected to warn sailors of the shoals (sandbars) off the Lake Huron coast. It is still functioning as an automated light. A restoration that eventually exceeded $2.3 million started in 2011 and the facility reopened for tourism in June 2015. The origin of the designation ''Imperial'' is not certain, but some historians speculate that because the towers were public construction built under the colonial administration while Canada was a self-gov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresnel Lens
A Fresnel lens ( ; ; or ) is a type of composite compact lens developed by the French physicist Augustin-Jean Fresnel (1788–1827) for use in lighthouses. It has been called "the invention that saved a million ships." The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet. The simpler dioptric (purely refractive) form of the lens was first proposed by Count Buffon and independently reinvented by Fresnel. The ''catadioptric'' form of the lens, entirely invented by Fresnel, has outer elements that use total internal reflection as well as refraction; it can capture more oblique light from a light source and add it to the beam of a lighthouse, making the light visible from greater distances. Description The Fresnel lens redu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
