Kj. Maloy et al., SOME FURTHER EXPERIMENTS ON THE TICKING H OUR GLASS, Comptes rendus de l'Academie des sciences. Serie II. Mecanique, physique, chimie, astronomie, 319(12), 1994, pp. 1463-1467
New experiments on the ticking hour glass are presented. We show that
this intermittent behaviour is due to the pressure difference between
the two chambers. We measured experimentally the fluctuations of the p
ressure in the lower chamber and fluctuations in the position of the f
ree arch just above the neck, and show that correlated oscillations ar
e observed.