I'm not sure if this is the right place to post this in, but I'm trying to recreate the "Deformation of water by a magnetic field" experiment by Chen et al. The PDF version of the paper can be accessed via Google (for some reason it won't let me provide a direct link). On the 2nd page of the paper, they do a Riemann sum to calculate the value for the depression of the water surface as a function of position, but I can't figure out how they got those values for Δh. For my experiment I've managed to obtain the Δy values, but I don't know how to go from there. Any help would be appreciated.