342 



On Currents in Water. 



Suppose it possible to project a body due nortb from the equator, 

 to reach the sixtieth degree of north latitude in one hour. 



Let EW (fig. 1.) represent the equator, and NS a meridian, on 

 which a body is projected from A, to reach B, in the sixtieth degree 

 of north latitude, in one hour, in which time the point A would be 

 carried to C, fifteen degrees eastwardly. Now, according to the 

 law respecting forces, the body thus impelled in two directions, viz. 

 towards B and C, would not move in a direction towards either, but 

 upon the diagonal line AD between them, arriving at the latitude of 

 sixty degrees north, at the distance of thirty degrees of longitude 

 eastwardly from the meridian upon which it was projected, equal to 

 fifteen degrees of longitude measured upon the equator. In this cal- 

 culation no allowances are made for resistances ; it is only used to 

 show that bodies passing northwardly or southwardly are deflected 

 from their course by the motion of the earth upon its axis. 



Upon the same principles, it may be shown, that a body projected 

 from the north pole towards the equator, would arrive at the latter 

 place upon the westerly side of the meridian upon which it was pro- 

 jected. 



This may be illustrated by causing a horizontal plane to revolve 

 about its center, when by rolling a ball upon it from the circumfer- 

 ence towards the center, it will be found to pass forward in the di- 



