75 



that are shot out from the equatorial belt, those directed east- 

 ward have the advantage of a rotational speed of i,ooo miles 

 per hour, while those inclined to the westward have an equal 

 disadvantage, a total difference of 2,000 miles per hour. Under 

 these conditions molecules shot eastward will more largely pass 

 into orbits than those shot against the rotation of the earth. It 

 is therefore inferred that the orbital molecules of the equatorial 

 tract moving in harmony with the earth's rotation will pre- 

 ponderate over those moving in the opposite direction, and that 

 there will be a larger number of these than of any other class 

 of orbital molecules. This view is strengthened by the fact 

 that the influences agitating the molecules in the equatorial 

 tract are more intense than those in higher latitudes. The earth 

 is therefore conceived to be surrounded by a belt of molecular 

 satellites revolving in the same direction as itself and having or- 

 bits at various distances from it out to the limit of control. 



What may be the quantitative value of these rare supplemen- 

 ary atmospheres is not here estimated. It is difficult to determine 

 from present data. There are suggestions that these atmos- 

 pheres have some appreciable value, in the great heights at 

 which meteorites become incandescent from atmospheric im- 

 pact and friction, and in the still greater heights to which the 

 aurora extends. Its streamers are held to be incandescent mole- 

 cules whose light springs from their ionization. Trigonometrical 

 measurements give them heights reaching to 600 and even 

 1,000 km. 



The profound function which the atmosphere plays in both 

 the organic and physical kingdom of the earth are thought to 

 be sufficient justification for tracing out its factors to any degree 

 of refinement and for using logical deductions where direct ob- 

 servation is impracticable. 

 i 



