Fig. 8. 



THE CAMERA LUCIDA. 



1. Origin of the name. 2. Its use. 3. Method of applying it. 4. 

 Explanation of its principle. 5. Precautions in using it. 6. Methods 

 of correcting the inversion of the object. 7. Amici's Camera. 8. 

 Magnitude of the picture. 9. Application of Camera to the 

 microscope. 



I. THIS instrument, which takes its name by contrast from the 

 camera-obscura, is one of the many gifts of the genius of Dr. 

 Wollaston to the arts. 



2. Like the camera-obscura, its chief, though not its only use, 

 is to enable a draughtsman by the mere process of tracing, to make 

 a drawing of an object. 



3. The observer places upon its table, a sheet of drawing 

 paper, and the instrument being placed level with his eye, he 



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