abstract:Fire arrows are an early form of gunpowder solid fuel rocket which were attached to a shaft of the arrow to provide a propulsive force. The Chinese are credited with both the invention of the fire arrow and also the first use of fire arrows in a military warfare.
Then he discovered a new Japanese method of cutting diamonds: When viewed under a low-magnification (3x) lens, the stone refracted light in such a way as to give off a pattern of eight heart-shaped sparkles at the bottom of the diamond and eight arrow-shaped fire-bursts through the top--hence the name "hearts-and-arrows" diamonds.