CuAr, XII.] OCEAN CURHENT?. 143 



resulting from the orbital motion. But, variations 

 in the effects alluded to as being in accordance with 

 what the theoretical consideration of the action of vis- 

 inertia3 indicates to be the natural result of an onward 

 motion of the earth, appear to show that the orbital 

 force is a partial cause of the effects observed. 



For instance, the effects apparent in the ocean, 

 instead of showing an annual change in the action of 

 vis-inertia3 from a northward to a southward direc- 

 tion, indicate a constant action northwards ; though 

 at the same time an annual variation in the northward 

 action, by which its action in March is greater than 

 in September, appears to show the influence of the 

 orbital force. 



And also, as regards the diurnal variation in the 

 action of the orbital force, there is not apparent such 

 a reversal from eastwards in the daytime to west- 

 wards at night-time as that which the sole action of 

 the orbital force would tend to cause. But there 

 are, however, apparent effects which indicate such 

 a change from an eastward action in the daytime 

 to a westward action in the night-time as accords 

 with the onward motion indicated by the north- 

 ward action and its variation above mentioned. 

 Because in such case the orbital motion being only a 

 component of the earth's true motion, and the latter 

 being not in the plane of the ecliptic, but inclined 

 southwards, more in the line of the poles ; then, in- 

 stead of a diurnal change from cast to west through 



