There's a figure that comes with the question but I'm having trouble attaching it so I will describe it the best I can. There is a large cylinder labeled the reservoir. A horizontal pipe is connected near the base of the reservoir and it is open at the other end so fluid flows out (point B). Then a small vertical horizontal cylinder labeled column 1 that is connected at about halfway of the horizontal pipe. What will be observed when a more viscous liquid, of the same mass density, is substituted for the less viscous liquid in the system? Answer: a lower fluid velocity at point B, but an unchanged fluid height in column 1. I've found 2 threads on this question on another site but I still don't understand how the height of column 1 remains unchanged if the fluid velocity is slower. Wouldn't that mean increased pressure meaning the fluid in column 1 will rise? Thank you!