A. As the air _absorbs and diminishes light_, the _higher we ascend_, the _less light will be absorbed_. Q. _Why does the SUN seem LARGER at his RISE and SET, than it does at NOON?_ A. Because the earth is surrounded by air, which acts like a _magnifying glass_; and when the sun is near the horizon (as its rays _pass through more of this air_), it is more magnified. [Illustration: Here SC represents a ray of the sun at noon, and MC a ray of the sun near the horizon. DEG represents the air or atmosphere around the earth. Because EC is longer than DC, therefore the rays of the sun at M pass through _more air_ than the rays of the sun at S, and the sun is more magnified.] Q. _Why does the RISING and SETTING MOON appear so much LARGER, than after it is risen higher above our heads?_ A. Because the earth is surrounded by air, which acts _like a magnifying glass_; and when the moon is near the horizon (as its rays pass through more of this air) it is more magnified. _(See last figure.)_ Q. _When CANDLES are LIGHTED, we CANNOT SEE into the STREET or road,--WHY is this?_ A. 1st--Because glass is a _reflector_, and throws the candle-light _back into the room again_; and 2ndly--The pupil of the eye (which has become _contracted_ by the light of the room) is _too small_ to collect rays enough from the dark street, to enable us to _see into it_. Q. _Why can't persons in the street SEE into a WELL-LIGHTED ROOM?_ A. Because the pupil of their eyes is _much dilated by the dark_, and cannot collect from the window sufficient rays to enable them to _see into the room_. Q. _Why do we often see the FIRE REFLECTED in our parlour WINDOW in winter time?_ A. Because glass is a _good reflector_; and the rays of the fire (striking against the window-glass) _are reflected back into the room again_. Q. _Why do we often see the shadow of our CANDLES in the window, while we are sitting in our parlour?_ A. Because the rays of the candle (striking against the glass) are _reflected back into the room_: and the _darker_ the night, the _clearer_ the reflection. Q. _Why is this reflection more clear, if the external AIR be DARK?_ A. Because the reflection is not then _eclipsed_ by the brighter rays of the sun _striking on the other side of the window_. Q. _Why is the SHADOW of an object (thrown on the wall) LARGER and larger, the CLOSER any object be held to the CANDLE?_ A. Because the rays of light _diverge_ (from the flame of a candle) _in straight lines_, like lines drawn from the centre of a circle. [Illustration: Here the arrow A held close to the candle, will cast the shadow BF on the wall: while the same arrow held at C, would cast only the little shadow D E.] Q. _When we enter a long AVENUE of TREES, WHY does the avenue seem to get NARROWER and narrower till it appears to MEET?_ A. Because the _further the trees are off_, the more _acute will be the angle_ that any two will make with our eye.