SKiLLiNG] NATURE-STUDY FOR THE SCHOOL 11 



Astronomy may seem at first thought too difficult a science 

 from which to draw material to be used in nature-study. Very 

 naturally a teacher untrained in astronomy will feel that a subject 

 so vast and intricate is more fitted, for the college student than the 

 elementary pupil. But this science which has been studied from 

 the infancy of the race is full of inspiration and stimulus for the 

 infant mind today. 



The first step to take in order to lead the child's mind out be- 

 yond the earth is to give him an idea of the solar system. Illustra- 

 tions are needful to this end ; verbal descriptions will not suffice. 



The simplest illustration is the blackboard drawing. No 

 diagram can be made to represent correctly all the relationships 

 of size and distance. Like a raised map, it is intended to be 

 suggestive rather than accurate as to scale. Different diagrams 

 should be used to represent different facts. 



For example, the relative distances of the planets is shown thus : 



Place at one end of the blackboard a dot for the sun. A dot 

 five inches from this will represent Mercury. Venus is shown 

 by a dot eight and one-half inches from the sun, the earth twelve 

 inches, Mars one foot nine inches, the Asteroids two feet nine 

 inches, Jupiter five feet, Saturn nine and one-half feet, Uranus 

 19 feet and Neptune 30 feet. (Fig. i). 



Circles cut from paper and pasted on the blackboard give at a 

 glance relative sizes of planets. 



The following are convenient diameters : Mercury three-eighths 

 inches, Venus one inch, Earth one inch, Mars one-half inch, 

 Jupiter eleven inches, Saturn nine inches, Uranus four inches, 

 Neptune four inches. (Fig. i). 



A most instructive model of the solar system is easily con- 

 structed from croquet balls suspended by cords as pictured in 

 Fig. 2. **S" the sun is made stationary by an attachment to the 

 floor. "E" and *T" revolve about "S", the suspension cord 

 twisting to allow motion. ' "M" the moon is carried around the 

 sun with "E", about which it revolves several times making several 

 months to the year. The ball 'T" may represent any planet 

 and may swing out farther from the sun than the earth or the 

 reverse. 



One of the most important observations to be made by pupils 

 is with the sun board shown in Fig. 3. A discussion of the sea- 

 sons is based upon a series of readings showing the apparent 



