We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
30 have no motion of its own, it would be drawn in a straight line towards the Sun, along the line A K. Now, by the combined action of these two tendencies, according to the laws of composition of forces , the Earth or other body will be impelled in a curved path. This curve may be a circle, of which A B is a part; but in order that it should be so, there must be an exact and constant balance between the two forces. If this pro- portion does not exist, or any cause alter it after it has once existed, a different curve will be the result. For suppose the attraction towards the centre to be such as would cause the body at A to fall towards the Sun as far as A l 7 , in the same time that it would have been carried by the projectile force to A 1, then it will be bent out of its straight course into the elliptical curve A b, the curvature being here greater than that of the circular orbit A B. In like manner, if the Sun’s at- traction would draw the Earth to 4', whilst its pro- jectile force would carry it to 2, it will be carried by the joint action of the two forces along the elliptical curve b c. Having arrived at c, it would proceed in the straight line c h, if uninfluenced by the force of gravi- tation which tends to draw it towards the Sun; just as a stone whirled round in a sling, flies off in a tangent from the joint of the circle at which it is let go. Under the influence of these two forces, it is carried onwards to d; and in like manner, by the joint influence of its tendency to proceed in the straight line d i, and of the attractive force of the Sun, it is carried onwards through e and f —its rate of movement continually increasing, as distance from the Sun diminishes, so that it performs in equal times (as formerly explained) the distances A b, b c, cd,de,ef,fg. The increased velocity thus acquired, however, now more than balances the in- creased attraction which is caused by the Earth’s nearer approach to the Sun ; and consequently the distance tends to increase again, and the rate of motion to diminish. For whilst the projectile force would carry