Bartolommeo Diaz was a Portuguese navigator. He died in 1500. He was named in 1486 commander of one of that long succession of exploratory expeditions which the Portuguese court had during the 15th century become distinguished for promoting. The two vessels composing the expedition sailed along the African coast until they reached Cape Negro at latitude 15 degrees 50 minutes south, where Diego Cam, a previous explorer, had stopped. At 29 degrees 8 minutes they anchored at a point to which they gave the name of Angra das Voltas (Bay of Detours). In sailing south from this point they doubled the Cape of Good Hope without knowing it, and landed at a bay on the east coast. Bartolommeo Diaz now wished to continue his voyage in order to discover the country of Prester John, but the sailors refused to accompany him. In again doubling the Cape he gave it the name of Cabo Tormentoso (Cape of Storms), which the king changed to its present designation. In 1500 Bartolommeo Diaz had command of a vessel in the expedition of Cabral which discovered Brazil. In returning home the vessel which he commanded was lost on the 29th of May, 1500. Research Bartolommeo Diaz
The inferior oblique is a thin narrow muscle that originates from the orbital surface of the maxilla and extends along the inner side of the eyeball. It helps move the eye sideways and rotates it slightly. The inferior oblique muscle works in conjunction with the other eyemuscles to move the eye. These muscles are anchored to the sclera near the cornea. The
inferior oblique muscle is innervated by the third cranial (oculomotor) nerve. Research Inferior Oblique
The striated muscle cells, which comprise about 40% of the body weight, are voluntary. They are mostly attached to the bones to move the skeleton and are fast acting and powerful. The voluntary muscles are of three series: those more or less arranged around the axial skeleton (head, neck, and trunk), and those nonsegmentally arranged around the appendicular skeleton (arms and legs), and those associated with the visceral skeleton (brachiometric muscles).
All muscles have basically the same structure. Each muscle has an attachment at both ends, called the origin and insertion, and a fleshy contractile part, called the muscle belly. The point of origin is the point of attachment where the muscle is anchored to the bone. The point of insertion is the attachment of the muscle to the bone it moves. These muscles are attached either directly or indirectly (via tendons) to the bones, and work in opposing pairs (one muscle in the pair contracts, while the other relaxes) to produce body movements (The muscles work together to produce movement of a joint, to steady a joint, and to prevent movement in the direction opposite to those intended.). As a rule, only the insertion bone moves. The shortening of the muscle as it contracts pulls the insertion bone toward the origin bone. The origin bone stays put, holding firm while the insertion bone moves toward it. These muscles always tire with continued use and require rest. Because of their cross-striped appearance under a microscope, these muscles are called striated.
There are two types of striated muscle: dark fibres and light fibres. The dark fibres are a deep red colour and predominantly produce slow, tonic movement. The light fibres are lighter in colour and predominantly produce quick and contracted motions. Each muscle fiber is encased in a thin, transparentmembrane called the sarcolemma. The fibres are subdivided longitudinally into minute fibrils and myofibrils encased in a fluid called sacroplasm. The muscle cells are elongated tubular structures with as many as several hundred nuclei and are actually fusions of cells (syncytia). The muscles are bound together in bundles of white fibrous connective tissue called perimysia. Striated muscles not directly under voluntary control include vocal cord muscles and the diaphragm. Research Striated Muscle
The teeth are formally considered as accessory digestive organs, but as they are both osseous tissue as well as integral to the structure of the skull. The average adult human has 32 teeth, with 16 of these being anchored in the maxilla and 16 in the mandible. Chewing is accomplished by moving the mandible in proximity to the maxilla so that the teeth of the two bones are brought together, cutting, grinding, and tearing food. The teeth are paired, with two of each variety in the top row and two of each in the bottom, with every tooth in the top row matching one in the bottom as well. In the adult, the sixteen teeth in a row consist of four incisors (two central, two lateral), two canines, four premolars, and six molars. In the child, however, the four premolars and the back two molars are missing in the deciduous teeth. Because it is usually between the age of 18-21 that the last two molars grow in, these teeth are often called 'wisdom teeth.' Research Teeth
The Battle of Aegospotami was a Spartan naval victory over the Athenians at the end of the Peloponnesian War 405 BC off Aegospotami. Lysander's decisive victory over the Athenian fleet broke the, until then unchallenged Athenian naval superiority and effectively ended the war. An Athenian fleet of some 180 triremes lay at Aegospotami and 170 Peloponnesian ships, under Lysander, lay at Lampsacus on the southern shore. On four successive days the Athenian fleet rowed across the strait, hoping to draw Lysander's force out to give battle, but without success. On the fifth day Lysander waited until the Athenians made their usual sortie and returned to their base; once they had anchored, Lysander's fleet made a sudden dash across the water, pounced on the anchored Athenians, captured 160 ships, and killed the crews. Research Battle of Aegospotami
A mulberry harbour was an artificial harbour built by the British during the Second World War to allow supplies to be off loaded in Normandy for the invading allied troops in 1944. Two mulberry harbours were constructed in two phases. First sixty block ships were sailed from Britain lined up bow to stern a the required location and scuttled to create a breakwater for the harbour. Next blocks of reinforced concrete were towed by tugs over and assembled into a harbour. After the concrete blocks (caissons) a floating wharf was anchored into position and floating pier heads positioned on the landside of the harbour. Finally, concrete and steel pontoons were connected to join the pier heads with the shore, forming a floating road. Mulberry A erected for the Americans off Omaha beach was destroyed by a stormhalfway through construction, but Mulberry B erected for the British at Arromanches survived storms far more severe than it was designed for and allowed millions of tons of men and supplies to be off loaded during the summer and Autumn of 1944 before it was closed in November 1944. Mulberry B at Arromanches measured two miles wide and one mile deep and took fourteen days to construct. Research Mulberry Harbour
The Royal Oak was a British first-class battleship of 14150 tons launched in 1892. The Royal Oak was a British Royal Sovereign Class dreadnought of 25750 tons displacement launched in 1914. She carried a complement of between 937 and 997 and was powered by a Hawthornturbine providing 40000 hp and a top speed of about 21 knots depending upon load. Armaments consisted of eight 15 inch guns, fourteen 6 inch guns, two 3 inch anti-aircraft guns, four 3 pounder guns, five machine-guns and four submerged 21 inch torpedo tubes. The Royal Oak was a British battleship of the Second World War. She was armed with eight 15 inch guns, twelve 6 inch guns, eight 4 inch anti-aircraft guns and sixteen 2-pounder anti-aircraft guns. She had a top speed of 21.5 knots. She carried a crew of 1146. She was sunk by U-47 whilst she was anchored at Scapa Flow on 13th October 1939. The name Royal Oak has been used in the British navy since 1663. Research Royal Oak
Torquay is a seaside resort town in Devon, England. Until 1790 it was a quiet fishing village, then during the Napoleonic wars it hosted the wives of Naval officers who were based on ships anchored at Torbay. From the middle of the 19th century it became a popular seaside resort. Research Torquay
A bridge, a structure of stone, brick, wood, iron or other material, affording a passage over a stream, valley, or the like. The earliest bridges were probably the trunks of trees. The simplest form of bridge is known as a clapper-bridge and consists of planks or slabs of stone which rest on piles of stones.
The arch seems to have been unknown amongst most of the nations of antiquity. Even the Greeks had not sufficient acquaintance with it to apply it to bridge building. The Romans were the first to employ the principle of the arch in this direction, and after the construction of such a work as the great arched sewer at Rome, the Cloaca Maxima, a bridge over the Tiber would be of comparatively easy execution. One of the finest examples of the Roman bridge was the bridge built by Augustus over the Nera at Narni, the vestiges of which still remain.
It consisted of four arches, the longest of 43 meters span. The most celebrated bridges of ancient Rome were not generally, however, distinguished by the extraordinary size of their arches, nor by the lightness of their piers, but by their excellence and durability. The span of their arches seldom exceeded 20 or 25 meters, and they were mostly semicircular, or nearly so.
The Romans built bridges wherever their conquests extended, and in Britain there are still a number of bridges dating from Roman times. One of the most ancient post-Roman bridges in England is the Gothictriangular bridge at Croyland, in Lincolnshire, said to have been built in 860, having three archways meeting in a common centre at their apex, and three roadways. The longest old bridge in England was that over the Trent at Burton, in Staffordshire, built in the twelfth century, of squared freestone, and pulled down in the 19th century. It consisted of thirty-six arches, and was 47 meters long.
Old London Bridge was commenced in 1176, and finished in 1209. It had houses on each side like a regular street until 1756-58. In 1831 it was altogether removed, the new bridge, which had been begun in 1824, having then been finished.
The art of bridge-building made no progress after the destruction of the Roman empire until the eighteenth century, when the French architects began to introduce improvements, and the constructions of Perronet (Nogent-sur-Seine; Neuilly; Louis XVI bridge at Paris) are masterpieces. Some of the stone bridges built in later times far surpass those of older times in width of span.
Stone bridges consist of an arch or series of arches, and in building them the properties of the arch, the nature of the materials, and many other matters have to be carefully considered. It has been found that in the construction of an arch the slipping of the stones upon one another is prevented by their mutual pressure and the friction of their surfaces; the use of cement is thus subordinate to the principle of construction in contributing to the strength and maintenance of the fabric. The masonry or rock which receives the lateral thrust of an arch is called the abutment, the perpendicular supports are the piers. The width of an arch is its span; the greatest span in any stone bridge is about 75 meters. A one-span bridge has, of course, no piers.
In constructing a bridge across a deep stream it is desirable to have the smallest possible number of points of support. Piers in the waterway are not only expensive to form, but obstruct the navigation of the river, and by the very extent of resisting surface they expose the structure to shocks and the wearing action of the water. In building an arch, a timber framework was used called the centre, or centering. The centering had to keep the stones or voussoirs in position until they were keyed in, that is, all fixed in their places by the insertion of the key-stone.
The first iron bridges were erected from about 1777 to 1790. The same general principles apply to the construction of iron as of stone bridges, but the greater cohesion and adaptability of the material give more liberty to the architect, and much greater width of span is possible. At first iron bridges were erected in the form of arches, and the material employed was cast-iron; but the arch has been generally superseded by the beam or girder, with its numerous modifications; and wrought-iron or steel was likewise found to be much better adapted for resisting a great tensile strain than cast-metal.
Numerous modifications exist of the beam or girder, as the lattice-girder, bow-string-girder, etc; but of these none is more interesting than the tubular or hollow-girder, first rendered famous from its employment by Robert Stephenson in the construction of the railway bridge across the Menai Strait, and connecting Anglesey with the mainland of North Wales. This is known as the Britannia Tubular Bridge. The tubes are of a rectangular form, and constructed of riveted plates of wrought-iron, with rows of rectangular tubes or cells for the floor and roof respectively. The bridge consists of two of these enormous tubes or hollow beams laid side by side, one for the up and the other for the down traffic of the railway, and extending each to about a quarter of a mile in length.
Other tubular bridges of interest are the Conway Bridge, over the river Conway, an erection identical in principle with the Britannia Bridge, but on a smaller scale; the Brotherton Bridge over the river Aire; the tubular railway bridge across the Damietta branch of the Nile, which has this peculiarity, that the roadway is carried above instead of through the tubes. The Victoria Bridge over the St Lawrence at Montreal, originally tubular, is no longer so, the upper portion having been reconstructed with an open track. It is nearly two miles in length, or about five and a half times as long as the bridge across the Menai Strait. A girderrailway bridge across the Firth of Tay at Dundee was opened in 1887, being the second built at the same place, after the first had given way in a great storm. It is 2 miles 73 yards long, has 85 spans, is 77 feet. high, and carries two lines of rails. The bridge over the Firth of Forth at Queensferry, was completed in 1889, and was the largest bridge built on the cantilever principle and was the first very notable example.
A cantilever is a structure the main feature of which is a projecting arm jutting out over the space to be spanned and supporting the roadway; and two cantilevers may be made to meet directly, or the space between may be bridged over by a girder connected with both. The cantilever principle has the advantage that it may be employed where there might be great difficulties in the way of a bridge otherwise constructed, since the projecting arm may be built out from either side of the river or other opening to be crossed, and at a great height if necessary. In some cases a bridge with an arch or arches of wrought iron or steel is preferred chiefly or solely because such a structure has a more handsome appearance than some other bridges.
American engineers have been very successful as builders of iron bridges, adopting various forms of girder, and constructing also some splendid bridges, with arches of great span, built up of wrought iron and steel.
Suspension-bridges, being entirely independent of central supports, do not interfere with the river, and may be erected where it is impracticable to build bridges of any other kind. The entire weight of a suspension-bridge rests upon the piers at either end, from which it is suspended, all the weight being below the points of support. Such bridges always swing a little, giving a vibratory movement which imparts a peculiar sensation to the passenger. The modes of constructing these bridges are various. The roadway is suspended either from chains or from wire-ropes, the ends of which require to be anchored, that is attached to the solid rock or masses of masonry or iron. One of the earlier of the great suspension-bridges is that constructed by Telford over the Menai Strait near the Britannia Tubular Bridge, finished in 1825. The cable-stayed bridge is a type of suspension bridge in which the supporting cables are connected directly to the bridge deck without the use of suspenders.
Though the oldest bridges on record were built of wood, like the Sublician Bridge at Rome, or that thrown by Caesar across the Rhine, it is only in certain places and for certain purposes that wood was much used after 1800. In the 19th century Germany was the school for wooden bridges. Perhaps the most celebrated of all wooden bridges was that which spanned the Rhine at Schaffhausen in Switzerland. This was 364 feet in length and 18 feet broad. It was designed and executed by Ulric Grttbenman, a village carpenter, in 1758, and was destroyed by the French in 1799. In the United States, where timber was still in common use in the 19th century, the Trenton Bridge over the Delaware, erected in 1804; the bridge over the Susquehannah, etc were examples of wooden bridges.
Trestle Bridges, or bridges the roadway of which is supported on wooden trestles or frames, formed of a series of beams and braces and often built up to a great height, were common in America until recently. Certain kinds of bridges are known as movable bridges. The bascule, balance, counterpoise or drawbridge - in which the roadway may be raised and lowered in one or two pieces, - is a common form; and there are also swing bridges (also known as pivot bridges) - opening horizontally to let shipping pass; bridges constructed so as to roll horizontally on wheels or otherwise; bridges in which the movable part, carrying the traffic, is suspended from a high iron framework or cables, under which shipping passes; these forming transporter bridges, as the bridge across the Mersey between Runcorn and Widnes, etc.
Pontoon or floating bridges are formed of pontoons or boats over which the roadway is laid, there being often the means of making an opening for shipping. A flying bridge is simply a kind of ferry. The Tower Bridge, London, crossing the Thames, is a unique structure, a combined suspension and bascule bridge, opening in the centre to admit ships, and originally having an elevated footway for passengers, with lifts and stairs in two towers.
The Bailey bridge is a temporary bridge made of prefabricated steel parts that can be rapidly assembled. It is named after its inventor, the Englishman Sir Donald Bailey who designed the Bailey bridge during the early-mid 20th century.
The Probert Encyclopaedia was designed, edited and programed by
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Abbreviations
Research Bartolommeo Diaz
