OXYGEN SUPPLY. 



51 



New York City, and the Lunkenheimer angle needle-valve were tight 

 to the pressure obtained in oxygen cylinders when filled to 100 atmos- 

 pheres or more. Threaded collars and fittings were obtained from the 

 manufacturers of the cylinders and substituted for the fittings on the 

 needle- valve; the needle- valves were then attached to the small 



TABLE 9. Correction factors of the Bohr meters, as shown by results obtained in actual use. 



oxygen cylinders. The cylinders, thus fitted, have been more or less 

 used since that time. 



It is somewhat difficult to state which method of measurement is 

 preferable, as both the cylinder method and the meter method have 

 their disadvantages. The use of the oxygen cylinder and valves 



