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 object had reached a distance which is as great as that between the moon and the earth, the sun's attraction would have surpassed the attraction of the earth.

Assuming that the body moved in a straight line with a speed of seven miles a second, it is easy to show that after eight or nine hours it would have passed more under the influence of the sun than it was under that of the globe from which it had taken its rise. It is, therefore, obvious that ere long the object would be so far affiliated to the sun that it would have practically renounced all connection with the earth, which would now mainly operate as a perturbing agent in its movement. The laws of dynamics assure us that under these circumstances the missile will continue to move in what is practically an orbit around the sun. The size of this orbit will depend upon the particular circumstances of the case.

Let us suppose that the initial velocity does not exceed a certain definite amount. Then it is plain that the figure in which the object is constrained to move must be an ellipse, the motion being performed in accordance with Kepler's laws, around the sun placed in the focus. The plane in which the little body moves as well as the time which the journey requires depends on the initial conditions as to speed and direction under which the projection took place. It is all-important for our present purpose to know that the orbit must cross the point from which the meteorite originally took its departure. Perhaps it would be more correct to say that it must pass in the vicinity of that point, for the attraction of the earth will no doubt slightly modify the initial circumstances of the movement, and indeed there are other perturbations which ought not to be overlooked. We