THE HOME YARD AND PLAYGROUND 391 



3. TO MAKE A BOX KITE. 



4. TO MAKE A SAILBOAT THAT WILL SAIL INTO THE WIND. 



5. TO MAKE A TOY AIRPLANE. 



6. To MAKE A RUSSIAN NINEPIN SET. 



7. TO LEARN TWENTY CONSTELLATIONS. 



The home yard and playground. Fortunate indeed 

 are the children who have a yard which is their own in 

 which to play. In many cities no such thing is possible, 

 and boys and girls must share with others the public play- 

 grounds where they are found. But every home yard, 

 no matter how tiny, ought to have some space devoted to 

 play. For little children a sand box with its load of clean 

 white sand gives pleasure the day long, and even grown- 

 ups like to build miniature roads or tunnels, and fight battles 

 with toy soldiers, in the make-believe land of the sand box. 

 For older boys and girls, if there is not room for ball, 

 croquet, or tennis, there is at least a place for the game 

 of quoits, tether ball, or Russian ninepins, even in the 

 back yard. Russian ninepins in partic- 

 ular is great fun, and requires a great 

 deal of skill. Tops and marbles have 

 been played by generations of small boys, 

 yet never lose their interest. The top is 

 also of scientific interest to us, for it 

 represents what is known as gyroscopic 

 motion. As the top spins, it resists the 

 force of gravity. As you doubtless 

 know, the instrument called the gyro- The gyroscope. 

 scope is used in many ways, especially 

 on large ships to prevent rolling in storms, in airplanes 

 to keep them upright, and in the new type of marine 

 compass. 



