We present a closed hydraulic system consisting of concatenated extended Pythagorean siphons in multi-stage configuration, in which a prolonged fluid transfer was observed (4 hours 30 minutes, 29 May 2021) toward levels higher than the source reservoir, with no external energy input. We describe an original mechanism — the EG Effect (Energia Gravitazionale) — whereby the gravitational descent in an extended siphon generates a dynamic sub-atmospheric depression propagating along the liquid column, actively drawing fluid upstream with intensity exceeding classical siphon predictions. Unlike the Mould effect (MULD), applicable exclusively to granular solids, the EG Effect is the first formalized principle describing the analogous mechanism applied to liquids in a tube configured for gravitational energy exploitation. We introduce the Gorelli Coefficient Gₑ = v²/ (gL), derived from the convective term of the unsteady Navier-Stokes equations. The model, calibrated on measured flow rate (0. 44 L/min), predicts a net elevation of 9. 2 cm, consistent with the empirical range of 5–15 cm. Energy balance confirms full compliance with the first law of thermodynamics.
Elvio Gorelli (Sat,) studied this question.