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.
As these inventions created new manufacturing and industry, many people also moved away from farms into cities. It was a time of very rapid change in the world. Date Event 1712 The steam engine is invented.Thomas Newcomen invents the first steam engine.ne of the most important inventions of the Industrial Revolution, steam engines power the first trains, steamboats, and factories. 1794 Eli Whitney patents the cotton gin. Eli Whitney creates a machine that makes it much easier to separate cotton seeds from cotton fiber.