30.105 J.W. Bloemer – J.A. Eibling – J.R. Irwin, Design of a basin-type solar still, (Battelle Memorial Institute, Columbus, Ohio, 19 may 1964). Step 15: With precast concrete beams in place, still ready for installation of distillate troughs and glass cover. For ease of installation of troughs, concrete blocks near lower beam in end walls should not be placed until the troughs have been installed.