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.
Horsepower is a unit of measurement that calculates power. It was originally coined by a Scottish engineer to compare the power of steam engines with the power of horses. This article will show you how to calculate the horsepower of your carâs engine, an electric motor, and your own body.orsepower is a unit of measurement that calculates power. It was originally coined by a Scottish engineer to compare the power of steam engines with the power of horses. This article will show you how to calculate the horsepower of your carâs engine, an electric motor, and your own body.