Radiant Heat and Light 



155 



FIG. 86. The concave mirror forms an image of the burning candle. 



How the microscope works. But the microscope is 

 different. It works like this : The first lens is put very 

 near the object which you are - examining. This lens 

 brings the light from the object to a focus and forms 

 an image, much larger than the object itself, high up in 

 the tube. If you held a piece of paper there you would 

 see the image. But since there is nothing there to stop 

 the light, it goes on up the tube, spreading as it goes. 

 Then there is another lens which catches this light 

 and bends it inward on its way to your eye, just as any 

 magnifying glass does. Next the lens in the eye forms 

 an image on the retina. The diagram (Fig. 84) will 

 make this clearer. (A real microscope is not so simple, 

 of course, and usually has two lenses wherever the dia- 

 gram shows one.) What actually happens is that the 



