THE GUI.F STREAM. 43 



examination, that he Lad shot south — that is, to the rigid (§ 103) 

 of his mark. In other words, tliat the path actually described 

 by the ball would be a resultant arisiug from this difference in 

 the rate of rotation and the trajectile force. Like a ray of light 

 from the stars, the ball would be affected by aberration. The 

 ball so shot presents the case of the passenger in the railroad car 

 throwing an apple, as the train sweeps by, to a boy standing by 

 the wayside. If he throw straight at the boy, he will miss, for 

 the apple, partaking of the motion of the cars, will go ahead of 

 the boy, and for the very reason that the shot will pass in 

 advance of the target, for both the marksman and the passenger 

 are going faster than the object at which they aim. 



120. Tendency of all currents hotli in the sea and air to move in 

 great circles a physical laic. — Hence we may assume it as a law, 

 that the natural tendency of all currents in the sea, like the 

 natural tendency of all projectiles through the air, is to describe 

 each its curve of flight very nearly in the plane of a great circle. 

 The natural tendency of all matter, when put in motion, is to go 

 from point to point by the shortest distance, and it requires force 

 to overcome this tendency. Light, heat^ and electricity, the 

 howling wind, running water, and all substances, whether ponde- 

 rable or imponderable, seek, when in motion, to obey this law. 

 Electricity may be turned aside from its course, and so may the 

 cannon-ball or running water; but remove every obstruction, 

 and leave the current or the shot free to continue on in the 

 direction of the first impulse, or to turn aside of its own volition, 

 so to speak, and straight it will go, and continue to go — if on a 

 plane, in a straight line ; if about a sphere, in the arc of a great 

 circle — thus showing that it has no volition except to obey 

 impulse ; and that impulse comes from the physical requirements 

 upon it to take the shortest way to its point of destination. 



121. This law recognized hy the Gidf Stream. — The waters of the 

 Gulf Stream, as they escape from the Gulf, are bound for the 

 British Islands, to the Xorth Sea, and Frozen Ocean (Plate IX.). 

 Accordingly, they take (§118), in obedience to this physical law, 

 the most direct course by which nature will permit them to 

 reach their destination. And this course, as already remarked, 

 is nearly that of the great circle, and of the supposed cannon- 

 ball. 



122. Shocds of NantucJcet do not control its course. — Many philo- 

 sophers have expressed the opinion — indeed, the belief (§ 116) is 



