26 F. L. Ekman, 



highest point should be 6™' above that at the mouth, it oiilj^ requires an 

 incHne of 1 in 90000. Now, according to the measurements of the to- 

 pographical corps, the difference between the rivers level at 14900 me- 

 tres from the mouth and the mean height of the water in the fjord 

 amounts to 27.6™', which indicates an incline of 1 in 54000; throughout 

 this distance the stream flows very uniform. If we further recollect that 

 a great part of the preponderant pressure at the mouth would be employed 

 in overcoming the friction of the outflowing fresh water-stream, so that not 

 even the whole of the above mentioned 6'^"'' water-pressure should be availa- 

 ble actually to drive the under-current forward, one cannot but conclude, 

 that the supposition, that the under-current described is urged forward 

 only by the difference of specific gravity, is in highest degree impro- 

 bable, whereas the vis viva of the surface-current is evidently a power 

 of sufficient energy to be capable of the effect here to be accounted for. 



A river may therefore, as regards its effect upon the sea-water at 

 its embouchure, be compared to a pump, the piston of which throws out 

 as much water as it sucks up from behind; the force, that sets the 

 pump-piston in motion, here corresponds to the river-waters vis viva. 

 This relation ought to be of practical importance to many maritime 

 towns, situated somewhat above the mouths of rivers. The sea-water, 

 which for many purposes it is important to obtain, has to be brought 

 from a distance of some miles to such towns, if it is to be taken from 

 the surface. But by the force, we have here described, it is actually 

 brought fresh and clear and almost undiluted right into the towns, where 

 it is wanted. 



With respect to the reaction-streams of rivers, lastly it deserves 

 to be noticed, that they must play an important part in the case of se- 

 dimental depositions and delta-formations at the mouths of rivers. But 

 as this question is foreign to the object of this essay, I shall not dwell 

 upon it. 



Inclosed ocean-basins, in which the rainfall exceeds the evapora- 

 tion are in fact nothing more than river-mouths of unusually large di- 

 mensions and we may therefore very reasonably expect to find again 

 there the same phœnomena, that I have described as taking place at the 

 mouth of Göta-elf, though on a different scale. If such a basin commu- 

 nicates with the ocean only by a narrow and relatively shallow channel, 

 we may also, if we like, consider the surface-current in that channel as a 

 new river, and the basin above it as a dilatation of the river. The 

 chief difference, which the phœnomena of the streams in such a locality 



