4 Wilde, Moving Force of Terrestrial and Celestial Bodies. 



projected horizontally near the earth's surface 

 with a velocity 4"936 miles (26,062 feet) per 

 second, would revolve round the earth con- 

 tinually without touching it. 



That 2490omiles ^ 5044! ^ 8407 minutes = the 

 4'936 miles 60^ 

 time of revolution of a body round the earth 

 with an angular velocity of 26,062 feet per 

 second {d). 



7. The mean distance of the moon according to 

 modern astronomy, is 6028 semi-diameters of the earth, 

 and the time of its revolution in respect to the fixed stars, 

 27 days, 7 hours, 43 minutes = 39343 minutes. Now as 

 the times and velocities of rotation are reciprocally 



equivalents of each other, we have ^^^^^ =468 as the 

 ^ 84™ -07 



ratio of the orbital times or velocities of a body revolving 



round the circumference of the earth and the moon's orbit 



respectively. Therefore 468 x 8407 = 39344"' = 27 days, 



7 hours, 44 minutes, for the time of the moon's orbital 



revolution. 



8. Again, from the square of 468, as a velocity, 

 divided by the moon's distance in semi-diameters of 



the earth we have T" 7^ = 3634, or reciprocally — 



60-28 ^ -"^ 3634 



the total moving force of a body revolving round the 



earth's circumference and the moon's orbit respectively, 



the numbers being the same as those deduced from the 



law of attraction of gravitation for the same distance. 



9. As the radius of the moon's orbit is 6o'28 semi- 

 diameters of the earth, we have with the earth's radius in 

 miles, 3964 X 2 X 60*28 X 3-1416= 1501370 miles for the cir- 

 cumference of the moon's orbit. Dividing this by the time 



