SIMPLE EXPERIMENTS IN OPTICS. 



667 



orange may be produced. Directions are given for using the top on 

 the lantern, and casting the colors on the screen, so that a great many 

 persons may see it at once. 



Fig. 10. Tue Color-Top. 



Another method of producing these recompositions is illustrated 

 in Fig. 11. We have here a square piece of board for a base, an up- 

 right block at the corner, two pieces of glass to which the dotted lines 



Fig. 11. Direct Rkco.mposition of TU!i Coloks 



run, and in which reflections are to be seen at the spots where the 

 lines meet, and three pieces of paper at A, B, and C, painted respec- 

 tively red, green, and violet. The image of A is supposed to go througb 



