102 SCENERY OF TUB HEAVENS. 



and the satellites move from west to east, and the satellites move nearly in the same piano 

 with the orbits of their primaries. Why these laws should be departed from in this in 

 stance is an inexplicable circumstance. As we know little of Mercury owing to his prox 

 imity to the sun, so we know little of Uranus owing to his remoteness. The proportion 

 of light and heat which reaches him is about ^jS-g that which the earth receives, but this 

 is equal to the illuminating power of several hundreds of our full moons. From his f;ir 

 distant sphere, the planet would fall if subject alone to the centripetal force, and require 

 an interval of nearly fifteen years to be precipitated upon the sun. 



The last discovered and farthest planet is at the enormous distance of 2800 millions of 

 miles from the sun, and marks the present boundary of the planetary system. Neptune 

 has a diameter of 37,500 miles, a period of revolution of 1G4 years, aud is certainly 

 attended by at least one satellite, first seen by Mr Lassell in 1816. 



A cursory view has now been taken of the individual members of the solar system. 

 The vastness of its area and the magnitude of its objects forcibly arrest attention. The 

 more, indeed, we become experimentalists in the scenery of the universe, the more 

 impressed we are with the imperfection of all human thought and language in relation to 

 its range, the dimensions of its structures, and conscious of the inadequacy of our 

 conceptions. In early life we form ideas of magnitude which are notoriously defective. 

 To childhood romping upon the village green the scene of its gambols presents an extensive 

 surface, and the hill-side from which the daisy and cowslip are plucked appears a 

 considerable elevation ; the experience of after years corrects these impressions. When 

 the man returns to the scenes of his youth, after having been long separated from them, 

 he is surprised at their altered aspect, and struck with the fallacy of his former views, 

 The green of the village seems but a span, and the eminence a hillock. After having 

 gazed upon the expanse of the Amazon, or the powerful current of the Mississippi, the 

 stream meandering through the meadows which once suggested an idea of amplitude, 

 inspires only a notion of insignificance. It is thus with us when the mind departs from 

 terrestrial regions, and studies the outlying realms of nature. The survey corrects and 

 expands its views. The fallacy of former conceptions of height, length, breadth, and 

 depth is felt, and, penetrating into space, the conviction becomes more distinct, at every 

 step, of the poverty of language to express, and the inadequacy of intelligence to grasp, 

 the real magnitude of the universe. To a Welsh goatherd Snowdon aud Cader Idris 

 have gigantic dimensions in comparison with the scale of his own bodily structure ; but 

 the sovereigns of his native wilds dwindle into dwarfishness in contrast with Mont 

 Blanc, Mont Rosa, or the Ortler-Spitz. Yet these are shorn of their attributes of 

 extension, massiveness, and grandeur, in the view of the great Andean chain. All the 

 inequalities, however, of the earth's surface taken together, are, proportionally to its 

 magnitude, but as a handful of dust sprinkled upon an artificial globe, while the earth 

 itself is but one of the smaller objects of the solar universe. 



The superficial extent of the earth includes upwards of a hundred and ninety-seven 

 millions of square miles, and its solid contents amount to two hundred and sixty thousand 

 millions of cubical miles. Huge as this ball is, it is but like Snowdon to Mont Blanc, 

 when contrasted with Jupiter, Saturn, or Uranus. The areas, and solid contents, of 

 these planets are about as follows : 



Area. Solid contents. 



Jupiter . . 24,884,000,000 square miles 368,283,200,000,000 cubic miles 



Saturn . . . 19,600,000,000 261,326,800,000,000 



Uranus . . 3,848,460,000 22,437,804,000,000 



Including the other planets and the satellites, their combined surface cannot be estimated 



