30) maintains the vibration in a way to be discussed later, and the opening 0 makes the lower end a loop. The modes of vibration in an open organ pipe may be exhibited by means of Koenig's manometric flames (Phil.
The pipe is provided with manometric flames at its middle point, and at one-quarter and three-quarters of its length.
This may be shown by furnishing the pipes with manometric flames placed in the same vertical line.
Have adopted as a normal thermometric scale the Centigrade scale of the hydrogen thermometer, having for fixed points the temperature of pure melting ice (0°C) and that of the vapour of boiling distilled water (100°C), under a normal atmospheric pressure; hydrogen being taken under an initial manometric pressure of 1 metre, that is to say, at 1000/750 = 1.3158 times the normal atmospheric pressure.