Search results
Results from the WOW.Com Content Network
A beam compass and a regular compass Using a compass A compass with an extension accessory for larger circles A bow compass capable of drawing the smallest possible circles. A compass, also commonly known as a pair of compasses, is a technical drawing instrument that can be used for inscribing circles or arcs.
The earliest Chinese magnetic compasses were possibly used to order and harmonize buildings by the geomantic principles of feng shui. These early compasses were made with lodestone, a form of the mineral magnetite that is a naturally occurring magnet and aligns itself with the Earth's magnetic field. [10]
A modern military compass, with included sight device for aligning. A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north.
According to Needham, the Chinese in the Song dynasty and continuing Yuan dynasty did make use of a dry compass. [17] The dry compass used in China was a dry suspension compass, a wooden frame crafted in the shape of a turtle hung upside down by a board, with the lodestone sealed in by wax, and if rotated, the needle at the tail would always ...
The Japanese paper-folding art of origami has been reworked mathematically by Tomoko Fusé using modules, congruent pieces of paper such as squares, and making them into polyhedra or tilings. [185] Paper-folding was used in 1893 by T. Sundara Rao in his Geometric Exercises in Paper Folding to demonstrate geometrical proofs. [186]
This sub-section is about paper making; for the writing material first used in ancient Egypt, see papyrus.. Paper: Although it is recorded that the Han dynasty (202 BC – AD 220) court eunuch Cai Lun (50 AD – AD 121) invented the pulp papermaking process and established the use of new materials used in making paper, ancient padding and wrapping paper artifacts dating from the 2nd century BC ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Rulers used in technical drawing are usually made of polystyrene. It is used for drawing lines and connecting points. Rulers come in two types according to the design of their edge. A ruler with a straight edge can be used with lead pencils and felt pens, whereas when a technical pen is used the edge must be grooved to prevent the spread of the ...