36 SCIENCE OF THE GREEKS. pt. i. 



be a discoverer yourself, you must not be content with 

 knowing what has been done, but must set to work as they 

 [ did, and observe and make experiments for yourself. 



Chief Works consulted. — Draper's * Intellectual Development in 

 Europe ; ' Lewis's * Astronomy of the Ancients ; ' * Encyclopaedia Bri- 

 tannica,' art. 'Astronomy ;' Herschel's "Astronomy;' Baden Powell's 

 'History of Natural Philosophy;' Lardner's * Cyclopjedia,' 1834; 

 Sprengel's 'Histoire de la Medecine,' 1815 ; Grant's * History of 

 Physical Astronomy ; ' Lange's * Geschichte des Materialismus ; ' Rees's 

 * Encyclopaedia ; ' Whewell's 'History of Inductive Sciences.' 



