In mathematics, a brachistochrone is the curve between two points through which a body moves under the force of gravity in a shorter time than for any other curve, that is the path of quickest descent. Research Brachistochrone
In geometry, a conchoid is a curve, of the fourth degree, first made use of by the Greek geometer, Nicomedes, who invented it for the purpose of trisecting an angle and duplicating the cube. Research Conchoid
Gaussian distribution is a random distribution of events that is often graphed as a bell-shaped curve. A gaussian distribution is used to represent a normal or statistically probable outcome. Research Gaussian Distribution
A hyperbola is a plane curve, one of the conic sections, formed by a plane that cuts both nappes of a right circular cone but does not pass through the vertex of the cone. A hyperbola has two U- shaped non-intersecting branches, identical in form, with the open parts facing in opposite directions; the arms of each branch separate as they recede. A hyperbola is also defined as the locus of all points, such that the difference between the distances from any point on the hyperbola to two fixed points, called the foci, is equal to a constant. Each branch contains one focus in its interior area; the line joining the foci intersects each branch in a point called a vertex. This line, or the segment between the vertices, is called the transverse axis. The line perpendicular to the transverse axis and passing through the point midway between the vertices, midway between the foci, is the conjugate axis. The two axes meet at the centre of the hyperbola, which is symmetric with respect to each axis and the centre.
A hyperbola has two asymptotes passing through the centre; an asymptote of a curve is a straight line with the property that the distance between it and the curve approaches zero as the curve recedes to infinity. A rectangular or equilateral hyperbola has asymptotes that are perpendicular to each other. The hyperbola has useful and important properties. In particular, the angle formed at a point on the hyperbola by the lines joining the point to the foci is bisected by the tangent to the hyperbola at that point. In astronomy, some orbits are hyperbolic in shape. The modern navigational device the loran also uses
hyperbolas. Research Hyperbola
An oxbow is a piece of wood comprising a concave curve between two convex curves, thereby resembling a bow in appearance, used as a collar for a yoked ox, the ends being fastened to the yoke. The term is used in furniture to describe draws and the like which have a similar serpentine shape. Research Oxbow
In terms of furniture, Queen Anne refers to a style of furniture popularised around the early 18th century of which there are a few distinctive features: the use of walnut; the use of the cabriole leg, which is a leg shaped in the form of a double curve with the upper part being convex and the lower part concave, and the leg ending in either a claw-and-ball or a paw foot and the use of marquetry, inlay, veneering, and lacquer work and carvings of scallop shells, scrolls, Oriental figures, animals, and plants to decorate furniture of the time. Chairs of the Queen Anne period often had a curved back (a splat back) so as to fit the small of the back. Research Queen Anne
Tractory is the curve in which a heavy particle moves when dragged at the end of an inextensible string by a body moving in a straight line. Research Tractory
The black poplar (Populus nigra) is a large deciduous tree native to Britain, with spreading branches that arch downwards, and a brown, later greyish- black coloured, deeply furrowed bark. The leaves are alternate and serrate and are triangular-ovate with a wedge-like base and flattened petioles. The reddish-brown coloured axillary buds are long and sticky and curve upwards at the tip. Black poplar is dioecious, with crimson coloured male and green coloured female flowers arranged in catkins that open in early spring before the leaves appear. The fruit is a capsule which releases seeds with a white pappus. Research Black Poplar
Eagle is the name given to several large birds of prey of the sub-family Aquilinoe of the great family Falconidae, which includes the eagles, falcons, and hawks. The eagle is popularly, though erroneously, regarded as the noblest and most courageous of the rapacious birds. In fact, as the eagle swoops down silently on suspecting prey without warning, it is neither noble nor courageous. The eagle soars to a greater height than any other European bird, from which circumstance the ancients considered it as the bird or messenger of Jove.
The genusAquila which includes the most typical eagles, is distinguished by its long and powerful bill, the curve commencing at the cere, by its wings reaching to the tip of the tail, and by its tarsi being feathered to the toes.
The imperial eagle (Aquila imperialis) of Central Europe is probably the species to which the popular belief in the courage, strength, and nobleness of eagles is to be traced. Aquila chrysaetus, the golden eagle, is the chief British species. It measures over 180 cm (6 feet) from tip to tip of the expanded wings, and 240 cm (8 feet) from the beak to the end of the tail. The adults have the body brownish, becoming darker with age; the feathers of the head and neck pointed, and of a golden-red hue. This species is found all over the northern hemisphere. It was once common in the Highlands of Scotland, but started becoming rare in the 19th century. The Kirghis and other tribes of Central Asia use the golden eagle to kill antelopes, foxes, and even wolves.
Another British eagle is the erne or sea-eagle (Haliaetus albicilla) found near the sea-coast or lakes, and feeding largely on fish. The general colour is greyish-brown, the head pale-coloured, the tail white.
The bald eagle (Haliaetus leucocephalus), found in North America and North-east Asia, is the symbol of the United States, though Franklin deplored the selection on account of the bald eagle's mean and dishonest habit of robbing the industrious osprey of the fish it has caught. Like all members of the genus his diet is less restricted than that of the true eagles; and he even takes carrion. Another eagle (Circaetus gallicus), the serpent eagle, Or short-toed eagle, ranges through Southern Europe, Asia, and especially North Africa. In structure and habits this bird approaches the buzzards. Research Eagle
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Aberrancy of Curvature
