28 Responses to The Real Origin of Viking Raids. 1  Well done! 2  Thank you for this article. 3  The shutting of the ancient trade routes to Rome and the East by the Holy Roman Empire was the principle reason that the Rus trade routes down the Volga were established. 4  Pingback: Daily Stuff 5-20-13 MjÃ¶lnir | Ancient Light's Daily Stuff.
By Anne Marie Helmenstine, Ph.D. Gunpowder or black powder is of great historical importance in chemistry. Although it can explode, its principal use is as a propellant. Gunpowder was invented by Chinese alchemists in the 9th century.Originally, it was made by mixing elemental sulfur, charcoal, and saltpeter (potassium nitrate).y Anne Marie Helmenstine, Ph.D. Gunpowder or black powder is of great historical importance in chemistry. Although it can explode, its principal use is as a propellant. Gunpowder was invented by Chinese alchemists in the 9th century.
The Watt steam engine, a major driver in the industrial revolution, underscores the importance of engineering in modern history. This model is on display at the main building of the ETSIIM in Madrid, Spain. The concept of engineering has existed since ancient times as humans devised fundamental inventions such as the pulley, lever, and wheel. Each of these inventions is consistent with the modern definition of engineering, exploiting basic mechanical principles to develop useful tools and objects.