OF BAKOX HUMBOLDT. 55 



and trace the history of these grand and 

 courageous explorations than Alexander von 

 Humboldt. Had he not, also, set out first 

 from the shores of Spain into the great ocean ? 

 Had he not visited the same parts where 

 Columbus first set foot upon the new con- 

 tinent ? 



The discovery of the western hemisphere 

 opened likewise new fields for astronomy. The 

 conquests of Columbus in geography were 

 contemporaneous with the discoveries of Coper- 

 nicus in astronomy. The use of improved 

 telescopes expanded the circle of human pene- 

 tration into immensity.* Kepler discovered 

 the mathematical laws by which the planets are 

 balanced in space, which had been anticipated 

 by Copernicus ; and lastly, the great science of 

 gravitation, discovered by Newton, changed 

 physical astronomy into a mechanism of the 

 heavens. 



* " Our range of vision has been in this way immeasurably 

 enlarged by the telescope and microscope : ingenious acoustic 

 instruments enable us to appreciate, to study, and record, 

 sounds which could never be mastered by our unassisted 

 ears : variations of temperature, electricity, are now made 

 sensible to observation by delicate contrivances, long before 

 our unassisted senses could take any note of such changes." 

 Prof. H. Hennesey's Essay, Science and Civilization. 



