The leaky reservoir
A few textbooks still misinterpret the old experiment designed to illustrate the relation of liquid pressure to depth. It consists of a tank of water with several holes in the sides. Water streams out from these holes in parabolic trajectories. Leonardo daVinci illustrated this in his notebooks.
The accompanying text explains that since the pressure is greatest at the bottom of the reservoir, the velocity water emerging from the lowest hole is greatest and therfore that stream "goes the farthest". This error is compounded if the illustration actually shows that stream going farthest.
Didaktikogenic Physics Misconceptions