LIBRARY 



OP 



USEFUL KNOWLEDGE. 



NATURAL PHILOSOPHY. 



POPULAR INTRODUCTIONS 

 TO NATURAL PHILOSOPHY. 



NEWTON'S OPTICS. 



DESCRIPTION OF OPTICAL 

 INSTRUMENTS. 



THERMOMETER AND PYRO- 

 METER. 

 ELECTRICITY. 

 GALVANISM. 

 MAGNETISM. 

 ELECTRO-MAGNETISM. 



"WITH 



AN EXPLANATION OF SCIENTIFIC TERMS, 





X. 



PATERNOSTER-ROW. 



