THE SOLAR SYSTEM. 91 



meht, which are placed within the reach of our own inge- 

 nuity and skill. No one surely would have dreamed of pro- 

 curing such an aid to the natural sight, any more than of 

 creating a new sense. It would have seemed like changing 

 the law of our being, and the condition in which we are 

 placed. We have, by means of this instrument, emerged, as 

 it were, from a prison. The mind has effected its enlarge- 

 ment, as an insect bursts its little tenement, and flutters 

 through the free air, and over the gay fields. 



Another change in this science, of the first importance, 

 was wrought by the genius of Kepler, who died in the year 

 1630. But the last and most important of all the revolutions 

 that have taken place in it, is that achieved by Newton. 

 There is no other instance of so signal a change in the opi- 

 nions and pursuits of the philosophic world. It may be com- 

 pared to those great and rapid conquests, by which new 

 boundaries and new laws have been given to states and king- 

 doms, and new directions to the industry and active employ- 

 ments of men ; with this difference, however, that these 

 have been made by violence, and with the aid and co-opera- 

 tion of others, while the revolution in the sciences effected 

 by Newton, was the silent, solitary work of an individual. 



Questions. — 1, What is astronomy ? 2. What is said of the im- 

 proved slate of this brancli of knowledge ? 3. What may be regard- 

 ed as most surprising in it ? 4. What is said of the first use and im- 

 portance of the telescope ? 5. What is said of Kepler ? 6. Of Newton ? 

 [Note. Nev\i;on died March 1727, aged 85.] 



LESSON 41. 



The Solar St/ stem. 



Or' bit, the path in which a celestial body moves. 

 Car'dinal, one of the chief officers in the church of Rome. 

 Inquisi'tion, a court established for the detection of heresj-. 



The true solar system consists of the sun and an unknown 

 number of opaque bodies, which revolve round the sun, and 

 some of which at the same time revolve round others. 

 Those which revolve round the sun only, are called primary 

 planets and comets. Those which revolve round a primary 

 planet, at the same time they are revolving round the sun, 



