WORLD HISTORY

Detailed explanation-1: -The magnetic compass was first invented as a device for divination as early as the Chinese Han dynasty and Tang dynasty (since about 206 BC). The compass was used in Song dynasty China by the military for navigational orienteering by 1040–44, and was used for maritime navigation by 1111 to 1117.

Detailed explanation-2: -Why did Chinese alchemists warn people to stay away from the powder they made with saltpeter? It was likely to explode. Which Chinese invention led to a reduction in the use of crossbows, swords, and spears in warfare?

Detailed explanation-3: -Why did so much innovation with gunpowder weapons occur in China in the 14th century? Chinese rebels need weapons to defeat their Mongol rulers. What was the goal of the Ming dynasty when it first took power in China in the 1300s?

Detailed explanation-4: -The new Chinese bridge used arches that were a smaller part, or part/section, of a circle. This made the bridges wider and flatter than half-circle arches could. Called a segmental arch bridge, the new type of bridge took less material to build and was stronger, also.