A thumb compass is a type of compass commonly used in orienteering, a sport in which map reading and terrain association are paramount. Consequently, most thumb compasses have minimal or no degree mar ...
There are two widely used and radically different types of compass. The magnetic compass contains a magnet that interacts with the earth's magnetic field and aligns itself to point to the magnetic pol ...
Bituminous coals are graded according to vitrinite reflectance, moisture content, volatile content, plasticity and ash content. Generally, the highest value bituminous coals have a specific grade of p ...
Historical sources dating to the 4th century describe the production of coke in ancient China. The Chinese first used coke for heating and cooking no later than the ninth century. By the first decades ...
Gutenberg was born in the German city of Mainz, the youngest son of the upper-class merchant Friele Gensfleisch zur Laden, and his second wife, Else Wyrich, who was the daughter of a shopkeeper. It is ...
Bi Sheng was a commoner and his ancestry and details were not recorded. He was recorded only in the Writings Beside the Meng Creek (夢溪筆談/梦溪笔谈 Mengxi Bitan, or Dream Pool Essays) by Chinese sch ...
As the historian Chen Dengyuan points out, much of Shen Kuo's written work was probably purged under the leadership of minister Cai Jing (1046-1126). For example, only six of Shen's books remain, and ...
Modern, factory-produced movable type was available in the late 19th century. It was held in the printing shop in a job case, a drawer about 2 inches high, a yard wide, and about two feet deep, with m ...
Letter punch and coins Movable type traces its origins to the punches used to make coins: the reverse face of a Tetradrachm Greek coin from Athens, 5th century BC, featuring various letters and the ow ...
Since the fibers of bamboo are very short (less than 3 mm (0.12 in)), they are not usually transformed into yarn by a natural process. The usual process by which textiles labeled as being made of bamb ...
More than 10 genera are divided into about 1,450 species. Bamboo species are found in diverse climates, from cold mountains to hot tropical regions. They occur across East Asia, from 50°N latitude in ...
A shell intended to produce a loud report rather than a visual effect. Salute shells usually contain flash powder, producing a quick flash followed by a very loud report. Salute shells can be anywhere ...
Further information: History of gunpowder and Four Great InventionsPreparing fireworks at Sayn Castle, Germany.Two ignited Catherine wheels spinning during a traditional Maltese feast.A ground firewor ...
The earliest fire lances were spear-like weapons combining a bamboo tube containing gunpowder and projectiles tied to a Chinese spear. Upon firing, the charge ejected a small projectile or poison dart ...
James Mill (1773-1836), in his The History of British India (1817), distinguished three phases in the history of India, namely Hindu, Muslim and British civilisations. This periodisation has been crit ...
