The Greeks knew it...
Challenging 'intuition' in ascending casting method:
One expects the bronze to nicely travel down the casting channel and then rise in the statue making use of each gate consecutively.
This simulation shows how higher gates 'do not take over' or let's say do not work harder than the lower gates.
Each gate is equally active because the flow running through each gate is proportional to the pressure difference existing between the shape (big rectangle) and the runner (vertical pipe)
This phenomenon explains how the bronze can freeze prematurely in the top part of the form and that is very important knowledge for the Founder.
He can then provide solutions to avoid 'disasters'.
By the way, the Greeks, 2500 years ago, already knew about this.