LENGTH OF THE YEAR. 23 



108 millions of miles, just as easily as at its 

 present distance of 96 millions : we can suppose 

 the earth with its present stock of animals and 

 vegetables placed where Mars or where Venus 

 is, and revolving in an orbit like one of theirs : 

 on the former supposition our year would become 

 twenty-three, on the latter seven of our present 

 months. Or we can conceive the present dis- 

 tances of the parts of the system to continue what 

 they are, and the size, or the density of the cen- 

 tral mass, the sun, to be increased or diminished 

 in any proportion ; and in this way the time of 

 the earth's revolution might have been increased 

 or diminished in any degree ; a greater velocity, 

 and consequently a diminished period, being re- 

 quisite in order to balance an augmented central 

 attraction. In any of these ways the length of 

 the earth's natural year might have been differ- 

 ent from what it now is : in the last way without 

 any necessary alteration, so far as we can see, of 

 temperature. 



Now, if any change of this kind were to take 

 place, the working of the botanical world would 

 be thrown into utter disorder, the functions of 

 plants would be entirely deranged, and the whole 

 vegetable kingdom involved in instant decay and 

 rapid extinction. 



That this would be the case, may be collected 

 from innumerable indications. Most of our fruit 

 trees, for example, require the year to be of its 



