The ancestor of this fluid flow device was first described in 1897 and 1898 by Hele-Shaw, who used it for investigations of fluid flow around ship hulls.

   The shape to be tested is held between two parallel glass plates about a millimeter apart. The reservoir above the test cell has a compartment to hold dye, and water flows into a larger, parallel compartment. The shiny metal septum between the two compartments has slots in the bottom that allow parallel streams of dye to be injected into the water. The dye streams then flow around the test object and the water drains out of the bottom.

   The airfoil mounted in the device is held at a positive angle of attack. Other demountable cells hold automobile body shapes (both boxy and streamlined), narrow orifices to study the vena contracta, and circular disks. The disks can be rotated to simulate the Flettner Rotorship mechanism.

   The apparatus is in the Kenyon College collection, and has certainly not been used since 1964. I tried it out recently and found that a wetting agent would probably be needed to make the water wet the glass plates. It was made by Central Scientific and cost $42 in 1940. Ten years later it was out of the catalogue.