378 Common Science 



579. When you look through a triangular glass prism, things ap- 



pear to be where they are not. 



580. Lye and hot water poured down a clogged kitchen drain- 



pipe clear out the grease. 



581. You can draw on rough paper with charcoal. 



582. When little children get new shoes, the soles should be 



scratched and made rough. 



583. You can get your face very clean by rubbing cold cream into 



it, then wiping the cold cream off on a towel or cloth. 



584. Soft paper blurs writing when you use ink. 



585. Water will flow over the side of a pan through a siphon, if 



the outer end of the siphon is lower than the surface of the 

 water in the pan. 



586. There is a loud noise when a gun is fired. 



'587. Colored cloths should be matched in daylight, not in artificial 

 light. 



588. Lamp chimneys are made of thin glass. 



589. When you sweep oiled floors, no dust flies around the room. 



590. The ocean is salty, while lakes are usually fresh. 



591. A glass gauge on the side of a water tank shows how high the 



water in the tank is. 



592. You burn your hand when you touch a hot stove. 



593. Pounding a piece of steel held horizontally over the earth 



and pointing north and south will make it become a magnet. 



594. When only one side of a sponge is in water, the sponge grad- 



ually gets soft all over. 



595. If we breathe on a cold mirror, a fine mist collects on it. 



596. Butter is kept in cool places. 



597. Water will boil more quickly in a covered pan than in an 



open one. 



598. Mucilage, glue, and paste all become hard and dry after 



being spread out on a surface for a while. 



599. You cannot see things clearly through a dusty window. 



600. In making fire grates it is necessary to have the bars free to 



move a little. 



