The reflecting power of glass is precisely the same by night as by day, and is always very feeble. But it appears to be greater by night, _because the surrounding darkness increases the apparent strength of the reflection_. 517. _How do we know that objects reflect light in every direction?_ Because if we _prick a hole in a card with a pin_, and then look through that small hole upon a _landscape_, we can see some miles of country, and some thousands of objects; every part of every object throughout the whole scene, must have sent rays of light the small hole pricked in the card. [Verse: "Such knowledge is too wonderful for me; it is high, I cannot attain unto it."--PSALM CXXXIX.] At one extremity of the landscape, viewed through the hole in the card, there may be a forest of trees; in the distance there may be hills bathed in golden light, and overhung with glittering clouds; in the mid-distance there may be a river winding its course along, as though it loved the earth through which it ran, and wished, by wandering to and fro, to refresh the thirsty soil; in the foreground may be a church, covered by a million ivy leaves; and grouping towards the sacred edifice may be hundreds of intending worshippers, old and young, rich and poor; flowers may adorn the path-ways, and butterflies spangle the air with their beauties; yet every one of those objects--the forest, the hills, the clouds, the river, the church, the ivy, the people, the flowers, the butterflies--must have sent rays of light, which found their way through the little hole in the card, and entered to paint the picture upon the curtain of the eye.