PLATE II.]

167. When these small particles, flowing from the Sun or from a candle,

fall upon bodies, and are thereby reflected to our eyes, they excite in

us the idea of that body by forming it’s picture on the retina[36]. And

since bodies are visible on all sides, light must be reflected from them

in all directions.

[Sidenote: The rays of Light naturally move in straight lines.

Astronomy Explained Upon Sir Isaac Newton's Principles And made easy to those who have not studied mathematics · 第 101 / 275 题