|
Schema For Vertical Declining Dials
Vertical declining dials are sundials that indicate local apparent time. Vertical south dials are a special case: as are vertical north, vertical east and vertical west dials. The word declining means that the wall is offset from one of these 4 cardinal points. There are dials that are not vertical, and these are called reclining dials. A sundial schema uses a compass and a straight edge to firstly derive the essential angles for that latitude, then to use this to draw the hourlines on the dial plate. In modern terminology this would mean that graphical techniques were used to derive \sin x and m\tan y and from it \sin x .\tan y . Basic calculation There are four basic angles that are needed to construct a vertical declining dial, Waugh described them such: * SD- Sub-style distance - this is the angle on the dial plate between the foot of the style and the vertical noon line. * SH- Sub-style height - this defines the slope of the style. It has no effect on the design o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sundial
A sundial is a horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the apparent position of the Sun in the sky. In the narrowest sense of the word, it consists of a flat plate (the ''dial'') and a gnomon, which casts a shadow onto the dial. As the Sun appears to move through the sky, the shadow aligns with different hour-lines, which are marked on the dial to indicate the time of day. The ''style'' is the time-telling edge of the gnomon, though a single point or ''nodus'' may be used. The gnomon casts a broad shadow; the shadow of the style shows the time. The gnomon may be a rod, wire, or elaborately decorated metal casting. The style must be parallel to the axis of the Earth's rotation for the sundial to be accurate throughout the year. The style's angle from horizontal is equal to the sundial's geographical latitude. The term ''sundial'' can refer to any device that uses the Sun's altitude or azimut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass-and-straightedge Construction
In geometry, straightedge-and-compass construction – also known as ruler-and-compass construction, Euclidean construction, or classical construction – is the construction of lengths, angles, and other geometric figures using only an idealized ruler and a pair of compasses. The idealized ruler, known as a straightedge, is assumed to be infinite in length, have only one edge, and no markings on it. The compass is assumed to have no maximum or minimum radius, and is assumed to "collapse" when lifted from the page, so may not be directly used to transfer distances. (This is an unimportant restriction since, using a multi-step procedure, a distance can be transferred even with a collapsing compass; see compass equivalence theorem. Note however that whilst a non-collapsing compass held against a straightedge might seem to be equivalent to marking it, the neusis construction is still impermissible and this is what unmarked really means: see Markable rulers below.) More formally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scale Of Chords
A scale of chords may be used to set or read an angle in the absence of a protractor. To draw an angle, compasses describe an arc from origin with a radius taken from the 60 mark. The required angle is copied from the scale by the compasses, and an arc of this radius drawn from the sixty mark so it intersects the first arc. The line drawn from this point to the origin will be at the target angle. Mathematics A chord is a line drawn between two points on the circumference of a circle. Look at the centre point of this line. For a circle of radius , each half will be r\sin\tfrac so the chord will be 2r\sin\tfrac. The line of chords scale represents each of these values linearly on a scale running from 0 to 60. Availability It appears on Gunter's scale and the Foster Serle dialing scales. The commercial company Stanley marketed a metal version (Stanley 60R Line of Chords Rule) in 2015. See also * Ptolemy's table of chords The table of chords, created by the Greek astronomer, geome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Bell & Sons
George Bell & Sons was a book publishing house located in London, United Kingdom, from 1839 to 1986. History George Bell & Sons was founded by George Bell as an educational bookseller, with the intention of selling the output of London university presses; but became best known as an independent publisher of classics and children's books. One of Bell's first investments in publishing was a series of ''Railway Companions''; that is, booklets of timetables and tourist guides. Within a year Bell's publishing business had outstripped his retail business, and he elected to move from his original offices into Fleet Street. There G. Bell & Sons branched into the publication of books on art, architecture, and archaeology, in addition to the classics for which the company was already known. Bell's reputation was only improved by his association with Henry Cole. In the mid-1850s, Bell expanded again, printing the children's books of Margaret Gatty (''Parables from Nature'') and Julia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hautes Alpes
Hautes-Alpes (; oc, Auts Aups; en, Upper Alps) is a department in the Provence-Alpes-Côte d'Azur region of Southeastern France. It is located in the heart of the French Alps, after which it is named. Hautes-Alpes had a population of 141,220 as of 2019,Populations légales 2019: 05 Hautes-Alpes INSEE which makes it the third least populated French department. Its is Gap; its sole is |
Piedmont
it, Piemontese , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 = , demographics1_info2 = , demographics1_title3 = , demographics1_info3 = , timezone1 = CET , utc_offset1 = +1 , timezone1_DST = CEST , utc_offset1_DST = +2 , postal_code_type = , postal_code = , area_code_type = ISO 3166 code , area_code = IT-21 , blank_name_sec1 = GDP (nominal) , blank_info_sec1 = €137 billion (2018) , blank1_name_sec1 = GDP per capita , blank1_info_sec1 = €31,500 (2018) , blank2_name_sec1 = HDI (2019) , blank2_info_sec1 = 0.898 · 10th of 21 , blank_name_sec2 = NUTS Region , blank_info_sec2 = ITC1 , website www.regione ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresco
Fresco (plural ''frescos'' or ''frescoes'') is a technique of mural painting executed upon freshly laid ("wet") lime plaster. Water is used as the vehicle for the dry-powder pigment to merge with the plaster, and with the setting of the plaster, the painting becomes an integral part of the wall. The word ''fresco'' ( it, affresco) is derived from the Italian adjective ''fresco'' meaning "fresh", and may thus be contrasted with fresco-secco or secco mural painting techniques, which are applied to dried plaster, to supplement painting in fresco. The fresco technique has been employed since antiquity and is closely associated with Italian Renaissance painting. The word ''fresco'' is commonly and inaccurately used in English to refer to any wall painting regardless of the plaster technology or binding medium. This, in part, contributes to a misconception that the most geographically and temporally common wall painting technology was the painting into wet lime plaster. Even in appar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schema For Horizontal Dials
A schema for horizontal dials is a set of instructions used to construct horizontal sundials using compass and straightedge construction techniques, which were widely used in Europe from the late fifteenth century to the late nineteenth century. The common horizontal sundial is a geometric projection of an equatorial sundial onto a horizontal plane. The special properties of the polar-pointing gnomon (axial gnomon) were first known to the Moorish astronomer Abdul Hassan Ali in the early thirteenth century and this led the way to the dial-plates, with which we are familiar, dial plates where the style and hour lines have a common root. Through the centuries artisans have used different methods to markup the hour lines sundials using the methods that were familiar to them, in addition the topic has fascinated mathematicians and become a topic of study. Graphical projection was once commonly taught, though this has been superseded by trigonometry, logarithms, sliderules and computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
-(full).svg "Click for more on -> Schema For Vertical Declining Dials")
.jpg "Click for more on -> Fresco")
