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.
In 1698, Thomas Savery, an English inventor, patented a device that allowed for the use of steam to pump water. The steam engine that he created was used to remove water from mines. This design was improved upon by English engineer Thomas Newcomen in 1712.he steam powered engine is the heart of the steam locomotive. In order to understand how the locomotive works, it is important to first understand how the steam engine operates. This involves water and fire, which is used to create heat.