164 PROF. OSBORNE REYNOLDS ON 



times and resistances for discharging pressures above six 

 atmospheres diminish, the continuity of regular law is 

 broken at both ends of the series of pressures^ just as it is 

 in the series of planetary distances and some other quanti- 

 tative phenomena of nature. 



XI. On the Flow of Gases. 

 By Professor Osborne Reynolds^ LL.D.^ F.R.S, 



Eead November 17th, 1885. 



I, Amongst the results of Mr. Wilde^s"^ experiments on 

 the flow of gaSj one, to which attention is particularly 

 called, is that when gas is flowing from a discharging 

 vessel through an orifice into a receiving vessel, the rate 

 at which the pressure falls in the discharging vessel is 

 independent of the pressure in the receiving vessel until 

 this becomes greater than about five tenths the pressure 

 in the discharging vessel. This fact is shown in tables 

 iv. and v. in Mr. Wilde^s paper : thus, the fall of pressure 

 from 1 35 lbs. (9 atmospheres) in the discharging vessel is 

 5 lbs. in 7"5 seconds for pressures in the receiving vessel, 

 ranging from one half-pound to nearly 5 or 6 atmospheres. 



With smaller pressures in the discharging vessel the 

 times occupied by the pressure in falling a proportional 

 distance are nearly the same until the pressure in the 

 receiving vessel reaches about the same relative height. 



What the exact relation between the two pressures is 

 when the change in rate of flow occurs is not determined 



* Proc. Manchester Lit. and Phil. Soc. Oct. 20, 1885, or present toI. of 

 Mem. p. 146. 



