176 THE NA TUKE-STUD Y RE VIE IV [ 3 : 6 - sept., .907 



equilibrium or the laws of equilibrium. The visible fact that an 

 egg will stand on end, and that, too, on the smaller end, and 

 that the boy or girl can make it stand, is a strong appeal to the 

 interest of the child and gives opportunity for the earnest teacher 

 to draw out a good many principles as to correct habits of walk- 

 ing and standing. But first learn to balance the egg before you 

 teach this lesson. 



A young lady -called my attention to an interesting modifica- 

 tion of the Cartesian diver experiment of the text-books. A 

 homeopathic vial half filled with water so that it floats when 

 inverted in water is put into a pint flask filled with water and the 

 flask tightly corked. The slightest pressure on the sides of the 

 flask causes the vial to sink to the bottom, and it will come to the 

 top or remain at the bottom or half way up, as the pressure is 

 varied. I have never known this to fail to interest a class, and 

 the important suggested lesson is that every boy and girl in the 

 class will float in the water just as truly as the vial; that they 

 cannot drown unless water gets into the lungs and makes them 

 sink, therefore, if accidentally thrown into the water, teach them 

 to lie on the back and not to breathe unless the nose is in the air, 

 and the mouth is kept shut, for so they cannot sink. How 

 much more valuable this lesson than any that can be taught 

 about plants or animals ? 



Make children absolutely sure that they are floating bodies 

 naturally and how quickly they will learn to swim. This experi- 

 ment suggests also the swimming of fishes, the principle of the 

 balloon, the fact that skim milk is heavier than new milk, in fact 

 so many interesting things that the teacher can use it for a series 

 of lessons, all valuable in the extreme in the after-life of the 

 pupils. 



A senior in our model school took a dozen large needles, a spool 

 of thread and a small magnet to her class-room, had the pupils 

 magnetize the needles by drawing them eye to point over the 

 south pole of the magnet and suspend them in different parts of 

 the room. Nearly every child perceived that the needles pointed 

 in one direction, and the word north became a reality in his 

 vocabulary. The teacher next took a small compass and told 

 them of how Columbus used the knowledge they had gained by 

 their needles to guide him in his voyage across the ocean when he 

 discovered America. 



