THE COMPOUND MICROSCOPE 



of light converge, after passing through the lens. 

 If now our object is further away from the lens than 

 its principal focus, a state of affairs that existed in 

 the case of our lens A A and the object CD, we 

 obtain a magnified, real but inverted image; if, 

 on the other hand, using the same lens if we wish, 

 the object is nearer to the lens than its principal 

 focus, we obtain a magnified virtual and erect 

 image. The form of image then depends on the 

 relative positions of lens and object and not on the 

 magnifying powers of the former. 



After this digression, we will see what happens 

 when we combine the diagram showing the real. 



t 



inverted image, formed by the lens AA with the 

 virtual erect image, formed by the lens BB« In 

 reality we will draw a diagram showing the path of 

 the light rays through our compound microscope. 



We have used the same lettering as in our previous 

 diagrams and we see that, also as before, a real, 

 inverted image C^D^ of the object CD is formed by 

 the lens A A and a virtual, erect image C^^ D^^ of 

 the image C^ D^ is formed by the lens BB, the object 

 CD being further from the lens AA than its prin- 

 cipal focus and the image C^ D^ being nearer to the 

 lens BB than its principal focus. One very im- 



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