## common perpendicular Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

... perpendicular Let l 1 and l 2 be two straight lines in space that do not intersect and are not parallel. The common perpendicular of l 1 and l 2 is the straight line that meets both lines and is perpendicular to...

## common perpendicular

## Historic Churches Quick reference

*David Hey*

### The Oxford Companion to Local and Family History (2 ed.)

...years of the 14th century until the Reformation and later a native style known as Perpendicular Gothic was developed. This is named after the perpendicular lines of the mullions in the windows (which were enlarged until they filled all the available space in the walls), but the style includes much more than that, e.g. flat lead roofs hidden behind battlements and pinnacles, long ranges of clerestory windows, and carved wooden roofs. See John Harvey , The Perpendicular Style, 1330–1485 (1978). In Ireland, Scotland, and Wales there are far fewer...

## 10 Paper Reference library

### The Oxford Companion to the Book

...to the fold and book spine, producing a *folio . A second fold, perpendicular to the first, will produce chain lines running perpendicular to the spine, and thus a *quarto . A third fold restores the original orientation, producing an *octavo , and so on. Once a single sheet has been identified, any watermark and countermark can be noted, and their relative positions in the sheet assigned. This should allow the sheet’s original dimensions to be estimated from a knowledge of common commercial sheet sizes, taking into account the trimming that is...

## running

## distance between two lines

## pyramid

## parish churches

## window

## perpendicular style Quick reference

### The Concise Oxford Dictionary of Archaeology (2 ed.)

... style [De] A style of architecture found in Britain in the late 14th century ad through to the 16th century ad in which there is a strong emphasis on the vertical elements of construction and decoration. Pointed arches common in earlier centuries are flattened and arches and windows become framed by rectangular outlines. Towers of great height are added to ecclesiastical buildings and ceilings and roofs are often richly...

## pyramid Quick reference

### A Dictionary of Physics (8 ed.)

...pyramid A solid having a polygonal base with n sides, each side forming the base of a triangle. The n triangles so formed have a common vertex. The axis of the pyramid is a line joining the vertex to the centre of symmetry of the base. If the axis is perpendicular to the base the solid is a right pyramid . A square pyramid has a square base and a triangular pyramid has a triangular base ( see tetrahedron ). The volume of a pyramid is one third of the base area multiplied by the...

## Lissajous figures Quick reference

### A Dictionary of Physics (8 ed.)

...Lissajous figures A curve in one plane traced by a point moving under the influence of two independent harmonic motions. In the common case the harmonic motions are simple, perpendicular to each other, and have a simple frequency ratio. They can be displayed by applying sinusoidal alternating potentials to the X- and Y-inputs of a cathode-ray oscilloscope . they are named after the French mathematician Jules Lissajous ( 1822–80 ). https://nationalmaglab.org/education/magnet-academy/watch-play/interactive/lissajous-figures-on-an-oscilloscope An interactive...

## distance between two lines ((in 3‐dimensional space)) Quick reference

### The Concise Oxford Dictionary of Mathematics (5 ed.)

...the distance between the two lines is the length of any line segment N 1 N 2 , with N 1 on l 1 and N 2 on l 2 perpendicular to both lines. If l 1 and l 2 are not parallel, there are unique points N 1 on l 1 and N 2 on l 2 such that the length of the line segment N 1 N 2 is the shortest possible. The length | N 1 N 2 | is the distance between the two lines. In fact, the line N 1 N 2 is the common perpendicular of l 1 and l 2...

## telecentric lens Reference library

*Graham Saxby and Angela Nicholson*

### The Oxford Companion to the Photograph

...the common focal plane. The depth of field is very small, and thus the stop has to be small; but as it is effectively a field stop, so that in general the angle of field is only a few degrees, this type of lens is used chiefly in scanning devices and confocal microscopy. Its importance lies in the fact that the magnification of the image is constant, regardless of its distance from the lens. Olympus's Four Thirds mount lenses are claimed to be near telecentric. One advantage of this is that the light rays that hit the sensor are close to almost perpendicular to...

## flint Reference library

*Patrick Goode*

### The Oxford Companion to Architecture

...Though almost indestructible, flint can be fractured in any direction, a process called ‘knapping’. When freshly knapped, flints are often jet black, but always retain a darker hue than when uncut. In the most inventive application, known as ‘flushwork’ and most common during the Perpendicular period, knapped flints are set into a framework formed by another material, usually limestone . A particularly fine example is the gatehouse of St Osyth Priory, Essex (late 15th century). Flint was always regarded as merely a substitute for brick, so that it was...

## gable Reference library

*Anthony Quiney*

### The Oxford Companion to Architecture

...northern 16th-century adaptation of Italian Renaissance forms. Similarly, a shaped gable comprises a series of symmetrical concave and convex quadrants, usually separated by steps. Both were common in Flanders and the Low Countries and much copied elsewhere, notably eastern England. A tumbled gable has sides comprising slanting courses of brickwork laid perpendicular to its slope instead of horizontally. Anthony...

## sunbathing Quick reference

### A Dictionary of Animal Behaviour (2 ed.)

...An aspect of * thermoregulation in which the animal controls its body temperature by selective exposure to the sun. It is common in land invertebrates and cold-blooded vertebrates. For example, the desert locust ( Schistocerca gregaria ) maintains a perpendicular * orientation to the sun during the morning and evening, when the air is cold, but turns parallel to the sun's rays during the day when the air is hot. Similarly, after cold nights, lizards ( Draco spp.) often seek sunlight, basking in the sun so as to raise their body temperature....

## projection Quick reference

### A Dictionary of Mechanical Engineering

...and vertical axes along which a component's actual dimensions are scaled, and an angled axis for receding depth along which the dimensions are often reduced to avoid the impression of distortion. In an isometric drawing (isometric projection) , one of the three mutually-perpendicular axes of the body coincides with a vertical axis and the two others are at ±120° with respect to it. There is no perspective in such projections and lengths retain their true scaled...

## projection Quick reference

### A Dictionary of Mechanical Engineering (2 ed.)

...and vertical axes along which a component’s actual dimensions are scaled, and an angled axis for receding depth along which the dimensions are often reduced to avoid the impression of distortion. In an isometric drawing ( isometric projection ), one of the three mutually-perpendicular axes of the body coincides with a vertical axis and the two others are at ±120° with respect to it. There is no perspective in such projections and lengths retain their true scaled...

## Grid Plan Reference library

### The Oxford Encyclopedia of Archaeology in the Near East

...Plan . A common way for excavators to make easy reference to a specific location on an archaeological site is by using a grid. The meaning of any archaeological information, such as an excavated object or architectural remain, is derived largely from its context, and a grid helps to identify that location and context. To form a grid, an arbitrary system of intersecting perpendicular lines is imposed on a site. The lines are usually established according to magnetic directions, running north–south and east–west. A mid-point for the grid is often set at the...