168 ANNUAL OF SCIENTIFIC DISCOVERY. 



Second. During the discharge the liquid molecules do not move 

 from the circumference toward the centre they fall. 



Third. In the experiments of M. Magnus and M. Perrot, where 

 they have observed a movement of rotation of the liquid mass, at first 

 sensible at the surface above the orifice, and an instant after the dis- 

 charge had commenced, this movement had existed before the dis- 



O ' 



charge. 



Fourth. The gyratory movement of a liquid mass, during the dis- 

 charge, observed by M. Perrot, was not an immediate effect of the 

 diurnal movement of the earth. 



Discussing afterward an opinion given by M. Babinet at the time 

 of the first experiments, that all the rivers of the northern hemisphere 

 have a tendency to the right side, as an effect of the movement of the 

 earth, M. Laroque arrives at this conclusion: that, "in the actual 

 state of science, the flow of liquids cannot render manifest, in any 

 case, the rotary movement of the earth." Scientific American. 



HYDRAULIC POWER. 



A wonderful example, says the London Mechanics' Magazine, 

 Sept., 1861, of what hydraulic pressure acting through suitable ma- 

 chinery can effect, is seen on the application of what is known as. 

 Armstrong's hydraulic apparatus at the Swansea docks. The pipes 

 which convey the water, at a pressure of seven hundred pounds to the 

 square inch, extend a mile and a half; the hydraulic power being 

 available at any point throughout this length. By this agency, ren- 

 dered so docile as to be almost within the control of a child, though be- 

 fore it the strength of the elephant sinks into insignificance, the gates 

 are opened, the bridges swung, the sluices worked, and all the hercu- 

 lean labors of the docks performed. Man, no longer a mere drudge, 

 exhausting his puny strength in endeavoring to counteract the forces 

 of nature, employs these forces one against the other, and renders them 

 obedient to his will. Mechanical science first taught how power 

 might be gained at the expense of speed : the steam engine and the 

 hydraulic press were an advance beyond this point of compromise, 

 placing unconditionally in the hands of man a power which can 

 scarcely be calculated as a multiple of a man's work in foot-pounds. 



The only important practical objection to the universal employment 

 of the stupendous power of hydraulic pressure wherever it may be 

 made available, is the danger arising from the necessary steam appa- 

 ratus erected in the vicinity of warehouses, in consequence of which 

 increased rates of insurance become chargeable. To remedy this ob- 

 jection, it has been proposed to establish central stations for the gene- 

 ration of hydraulic power, and to distribute this by means of mains 

 laid along the principal thoroughfares in proximity to wharves and 

 warehouses, to which the power required for working cranes and 

 hoists, or for any other purpose, would be conveyed by branch pipes. 

 Thus a motive-power of any amount, certain in application, and under 

 perfect control, would become available, with the advantage, in point 

 of safety and economy, of dispensing with separate steam power for 

 each establishment. 



The full importance of the results which would follow the applica- 



