14 Reynolds, Dryness of Saturated Steam. 



So that to insure a gaseous state, all that is necessary 

 is to gradually diminish the pressure in the receiving 

 vessel, maintaining that in the first vessel, until the 

 temperature T 2 ' in the receiving vessel becomes constant. 



The only doubt is whether this point can be practically 

 reached, and this can only be determined by experiments. 



The remarkable circumstance in the flow of gases, of 

 which I published the explanation in a paper read before 

 this Society in 1885, that when steam or gas flows through 

 a restricted channel from one vessel into another, in which 

 the pressure is less than half that of the first, the quantity 

 which passes is independent of the pressure on the 

 receiving side, must have an important place in simpli- 

 fying the apparatus required for such experiment. 



Thus, with boiler pressure on one side of an orifice 

 opening into a vessel from which its escape is allowed by 

 an adjustable valve, the whole experiment can be regulated 

 by this valve, the quantity flowing through remaining 

 constant for all pressures after the half is reached. 



The only precautions necessary for accuracy are those 

 to secure approximately small velocities at the points where 

 the temperature is measured, and those to render small 

 the loss of temperature in the steam by radiation. And, 

 although these must complicate the appliances, they 

 appear to be practical. I may also notice that, should 

 such experiments be accomplished, they will afford the 

 means of verifying or correcting Rankine's value for Ci, 

 which he has only given as a probable approximate value. 



I hope these experiments may shortly be made, as 

 Mr. J. H. Grindley, B.Sc, Fellow of Victoria University, 

 has undertaken the research in the Whitworth Engineer- 

 ing Laboratory, Owens College. 



