Exploring the boundary between the siphon and barometer in a hypobaric chamber

Siphons have been used since ancient times, but exactly how they work is still a matter of debate. In order to elucidate the modus operandi of a siphon, a 1.5 m high siphon was set up in a hypobaric chamber to explore siphon behaviour in a low-pressure environment. When the pressure in the chamber was reduced to about 0.18 atmospheres, a curious waterfall-like feature appeared downstream from the apex of the siphon. A hypothesis is presented to explain the waterfall phenomenon. When the pressure was reduced further the siphon broke into two columns - in effect becoming two back-to-back barometers. This experiment demonstrates the role of atmospheric pressure in explaining the hydrostatic characteristics of a siphon and the role of molecular cohesion in explaining the hydrodynamic aspects.

Das Wirtschafts-Barometer: Mai 1935

Jaques Adler

Das Wirtschafts-Barometer: Juni 1935

Jaques Adler

Das Wirtschafts-Barometer: Juli 1935

Jaques Adler

Das Wirtschafts-Barometer: Dezember 1935 : Monatsbericht über den Palästina-Markt

Jaques Adler

Das Wirtschafts-Barometer: Jänner 1936

Jaques Adler

Das Wirtschafts-Barometer: Februar 1936 : Monatsbericht über den Palästina-Markt

Jaques Adler

Das Wirtschafts-Barometer: Mai 1936

Jaques Adler

Das Wirtschafts-Barometer: Juli 1936

Jaques Adler