4S6 The Phcenowena of GruviKtlion proved to he proximate 



„.b.. 



Suppose E to be the earth ; AB a portion of its orbit ; F a 

 place on the earth's surface ; C a stratum of the atmosphere 

 which a projectile has reached ; a l> a. parallel of the orbit, and 

 DE a tangent of the atmosphere ; then it is evident that, whether 

 the earth is turning from D towards E, or from E towards D, a 

 deflection, from the orbicular motion to the rotary, would take 

 place, measured by such an angle as DCc, or hCE, in either case 

 creating a direction of force opposed to that in the orbit, and 

 producing a resistance in the next*superior atmosphere, and 

 creating a deflection downward fully equal to the known pha;- 

 nomena, which requires for the first deflection but an infinitely 

 small portion of an angle of 20 seconds. 



It is also evident that the common rotary motion of the earth 

 and atmosphere would confer a greater velocity on the circle C 

 than the circle F, and so in every circle from C to F, the spaces 

 described being as the squares of the radii, or as the squares of 

 the distances from E. To confer, however, an equal momentum 

 on the mass, it is necessary that the densities from C to E should 

 be inversely as the velocity, or inversely as the spaces, or in- 

 versely as the squares of the radii. 



Moreover, as by the phaenomcna, the momenta in every con- 

 centric stratum or circle of rotation are known to be equal, so 

 any mass of equal density would in different circles, ur at different 

 distances, be carried or impelled in the vortex by the circum- 

 ambient media, or incumbent bodies, through spaces, which 

 would be to each other, inversely as the squares of the distunee 

 from the centre, and directly as the resistance of the medium in 

 ivhich they move. 



Consequently, the collision of the bodies or masses of different 

 densities, in the terrestrial system, will force or urge the heavy 

 bodies towards the centre, and of course, also, the light ones to- 

 wards the circumference— circumstances which we know accord 



with 



