Fig. 7. The Color Spectrum
Fig. 8. Reflection Angle
"When you throw a ball against a wall at an angle, it bounds away at the same angle. That is reflection, and is just exactly what light does when a ray strikes a mirror. If, on the other hand, the glass had no mercury on it to reflect the light, the ray would not go straight through, but would bend, just as you have seen a stick in a glass of water appearing as though it was bent below the water line. That is refraction."
Two weeks of very vigorous work had now been put in since the yaks had disappeared, and the wagon was still at the edge of the forest. George was anxious to recover it, with the new team, and with Harry started out early in the morning to make up as much as possible lost time, as every hour was considered valuable in their enterprises.
The yaks could be ridden as well as horses, but the greater part of the way were driven. One of the guns which had been completed was taken along, as well as the only pistol which the Professor had saved. In less than three hours the forest was reached and they were soon within sight of the wagon.