Thomas 5 Potter's (1975) apparatus for low pressure (1-3 kN/m) measurements is shown in Figure 3 . Feed reservoir R was controlled by air flow
through needle valve V. A steady rate of 1 drop/sec was allowed to flow through E. This setup, like the previous one, relied on the system of reservoirs to reduce vibrational interferences . The wavelength was measured from images on photographic plates (see Figure 4) using a Beck microscope with a
reading of 2μm. Figure 4) using a Beck microscope with a reading of Amplitude measurements were taken from the camera angle directly above the jet . A calibrated wire gauge mounted above the stream allowed for the direct calculation of distances.