The Birmingham age-herald., 1924-01-15
PRESIDE SCIENCE
Eaueatieaaa Hsntertaanmene


 When your intellectual friends come to call. instead of turning on the victoria. or showing them the album, try entertaining them with a few simple problems .n fireside science.
 Problem 1.-How many pennies can be placed in a full glass of water without the water running Over2 First make sure yourself. Fill a glass level full of water, and drop pennies one at a time into k- Top will find that as many as 60 or 70 pennies dropped into the water will not cause 1t to overflow. On the other hand. you cannot empty . glass of water into another glass con- taining 60 pennies. without spflling some of the water. Sixty ponies oc- cupy quite some space: and. as the glass was full of water before you began dropping pennies into if. you seem to be making two substances occpy the same space at the same time, which of course cannot be true. The right explanation will occur to you, if you take the trouble to read up on the surface tension of water Problem a-If the earth's equator were a solid steel hoop and you should cut it and insert one addition al foot, how far would the enlarged hoop stand away from the surface all around? Let's assume that the earth is a perfect sphere. exactly and that the hoop fits tightly. like the hoop of a barrel After the ad- dition of one foot. the hoop would be 24,0o0 miles and one foot long. How far will this hoop stand away from the surface all around Most persons will say the addition of one foot to a 24.oo0-mile circle would make no perceptible difference; bu: you will find that this enlarged circle stands away from the earth nearly two inches This statement Is easily proved with a pencil: for ev- cry foot added to the circumference of a circle lengthens the diameter nearly four inches in all. or nearly two inches at each end By divt0ing the number of added there's by 3,141s the exact distance the enlarged circle will be pushed away from the smaller circle may be determined As . mat ter of fact, the result is the same regardless of the size of the circle. If your original circle is only one nearly two inches at each end and this fact can be demonstrated by means of rulers drawing circles on paper), or with strings
 Problem s.-Since a mirror changes our right hands into left hands. right eyes into left eyes. etc. why should 1t not turn us upside down? If you lie down and look into the mirror with one eye directly above the other eye, your right side becomes your left side. feature for feature. yet mirror does not stand us on our heads. The reason will be found. if you do some thinking. A lighted candle, standing at one side of a mir TOT, appears to be behind 1t, ana . person unacquainted with light re- flection would believe the candle ac- tually stood behind the mirror
 Problem 4.-BIindfold A person and click pennies. or still better click castinets Zone sharp click) directly in front or directly behind his head. and you will see how easily ones sense Of direction may be deceived The clicking must be done in the plane Of the '-median line" which runs up and down through the nose. chin and centre of the forehead. for if the sound comes from either side the direction will be located In like manner preconceived opinions are honestly deceived by many scientific truths. A blindfolded person would swear that a sound, which a half dozen spectators see produced within a few inches of his nose. comes from the back of his head