48 Dr Andrew Fyfe on the Comparative Value of - 



Again, if this be true, then, under diffei'ent pressures, the 

 escape should be as the square roots of the pressures ; and, 

 accordingly, the time for equal consumpts should be inversely 

 as the roots of these pressures. 



To put this to the test of experiment, I procured a pla- 

 tinum jet, furnished with a graduated pressure gauge, and 

 adapted it to an experimental metre, by which I could con- 

 sume the gas, under the same and different pressures, and 

 mark the quantity consumed in a given time ; and conse- 

 quently the times for the consumpt of equal quantities. The 

 gauge had a vernief fitted to it, by which I could easily read 

 off to one-hundredths of an inch. The temperature and baro- 

 meter were also noted for each experiment, and the specific 

 gravity, when necessary, was ascertained in the usual way. 



The following are the results of trials made for the pur- 

 pose of putting these opinions to the test. 



Consumpt of Gases under different Pressures. 



Numerous experiments were made for ascertaining this, 

 first with gauges of small diameter, the results of which did 

 not agree with each other; but when the diameter was about 

 half-an-inch, they more nearly corresponded. 



I give the following from among many : — 



