ALEXANDER VON HUMBOLDT 353 



of South and Central America and Mexico. He was the first, so it is 

 claimed, to mark the decrease in intensity of magnetic force from the 

 poles to the equator. At any rate, his journey to the tropical possessions 

 of Spain in the new world gave a very decided impulse to the study of 

 natural history. 



It is not strange that a man with his extensive knowledge, his 

 varied experience as a traveler and the resources of the scientific and 

 literary world at his disposal should desire to write and publish a 

 work that should set forth in clear and accurate form all that in his 

 time was known of the earth and the celestial bodies. If any man was 

 ever justified in the belief that he could satisfy his ambition in this re- 

 spect it was Alexander von Humboldt at the age of seventy-sLx. 



" Cosmos " is a history in outline of the physical contemplation of 

 the universe. Its aim is to show the unity of the universe. It is not a 

 history of the natural sciences as such, rather an attempt to point out 

 the close connection of all the forces of nature. To do this all pos- 

 sible sources of information are laid under tribute. In his study of 

 what has been done and is now known, Humboldt pledges himself to 

 follow three laws, or to be guided in his thought and writing, by three 

 principles: viz., 



1. To show the efforts of reason, through meditation upon phe- 

 nomena to obtain a correct knowledge of natural laws. 



2. To consider events which have suddenly enlarged the horizon of 

 observation. 



3. To show what has been the result in the enlargement of the 

 fields of human knowledge through the discovery of new means of 

 sensuous perception, or of new organs, or instruments by means of 

 which we are brought into closer touch with terrestrial and celestial 

 objects. Thus in the telescope and the microscope we have new organs 

 of perception. 



Starting from the basin of the Mediterranean, with its three con- 

 tiguous closed seas and its three peninsulas, Spain, Italy and Greece, 

 the discoveries made by voyages to other countries are named, and the 

 fact stated that the earliest civilizations were developed in countries 

 rich in rivers, as Egypt, Messopotamia, India and China. The author 

 takes pains to emphasize the exceptional men who lead in new move- 

 ments in travel, who make startling and important discoveries. Nor 

 does he overlook the events which mark the beginning of new eras in 

 the world's history. He has the rare faculty of making us see how 

 striking contemporaneous events often are. For example, when Co- 

 lumbus discovered America, Copernicus was studying astronomy with 

 Brudzewski in the University of Cracow. The rapid extension of 

 knowledge at the beginning of the seventeenth century was due to the 

 studies and discoveries of Galileo and Kepler, at its close to those of 

 Newton and Leibnitz. It was in this century that the problems of 



