翻訳と辞書 Words near each other ・ History of submarines ・ History of Sudan ・ History of Sudan (1821–85) ・ History of Sudan (1956–69) ・ History of Sudan (1969–85) ・ History of Sudan (1986–present) ・ History of Suffolk ・ History of Suffolk, Virginia ・ History of Sufism ・ History of sugar ・ History of suicide ・ History of suits ・ History of Sulzer diesel engines ・ History of Sumer ・ History of Sunderland A.F.C. ・ History of sundials ・ History of supercomputing ・ History of superconductivity ・ History of supernova observation ・ History of surface transit in Northern Virginia ・ History of surface weather analysis ・ History of surfing ・ History of surgery ・ History of Suriname ・ History of surveillance ・ History of sushi ・ History of Sussex ・ History of Sussex County, New Jersey ・ History of sustainability ・ History of Svalbard Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク History of sundials ： ウィキペディア英語版 History of sundials A sundial is a device that measures time by using a light spot or shadow cast by the position of the Sun on a reference scale. As the earth turns on its polar axis, the sun appears to cross the sky from east to west, rising at sun-rise from beneath the horizon to a zenith at mid-day and falling again behind the horizon at sunset. Both the azimuth (direction) and the altitude (height) can be used to create time measuring devices. Sundials have been invented independently in all major cultures and become more accurate and sophisticated as the culture developed. ==Introduction== A sundial measures local solar time. Before the coming of the railways in the 1830s and 1840s, local time was displayed on a sundial and was used by the government and commerce. Before the invention of the clock the sundial was the only source of time, after the invention, the sundial became more important as the clock needed to be reset regularly from a sundial- as its accuracy was poor. A clock and a dial were used together to measure longitude. Dials were laid out using straight edges and compasses. In the late nineteenth century sundials became objects of academic interest. The use of logarithms allowed algebraic methods of laying out dials to be employed and studied. No longer utilitarian, sundials remained as popular ornaments, and several popular books promoted that interest- and gave constructional details. Affordable scientific calculators made the algebraic methods as accessible as the geometric constructions- and the use of computers made dial plate design trivial. The heritage of sundials was recognised and sundial societies were set up worldwide, and certain legislations made studying sundials part of their national school curriculums. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「History of sundials」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.