NOVELTY - A solar energy collection assembly comprises elongated light-absorbing floor mechanism for absorbing sunlight, elongated light-transmitting roof mechanism (11, 18) for allowing transmission of sunlight, elongated light-transmitting air partition mechanism for partially dividing enclosure into two tubular air ducts, and circulating mechanism for circulating air in enclosure.    USE - For distilling fluid (claimed).    ADVANTAGE - The invention is able to achieve a higher maximum temperature in its evaporator air duct, and higher maximum temperature differential between the warm end of its evaporator air duct and the cool end of its condenser air duct with a consequent higher rate of distillation.    DETAILED DESCRIPTION - A solar energy collection assembly comprises elongated light-absorbing floor mechanism for absorbing sunlight, elongated light-transmitting roof mechanism for allowing transmission of sunlight, elongated light-transmitting air partition mechanism underlying the roof mechanism and overlying the floor mechanism for partially dividing enclosure into two tubular air ducts, and circulating mechanism for circulating air in enclosure to cause the air to enter the lower evaporator air duct (15) through the first opening. The floor mechanism is overlain through a layer of feedstock fluid. The roof mechanism is situated above the floor mechanism and fixedly attached at its perimeter to the floor mechanism to form an enclosure. The tubular air ducts comprise upper condenser air duct (16) and lower evaporator air duct. The air partition mechanism is fixedly attached along its perimeter to the roof mechanism. It includes first opening near one of its opposite extremity, and second opening near its opposite extremity to allow the free flow of air between the upper and lower air ducts. The circulating mechanism propels air with sufficient velocity to induce thermal gradients along the lengths o the upper and lower air ducts. The gradients have a temperature differential sufficient to induce the progressive evaporation of feedstock fluid along the length of lower evaporator duct, and progressive condensation of the vapor of the fluid along the length of the lower evaporator duct to produce a fluid condensate. They have their hotter ends near the second opening and their cooler ends near the first opening.    DESCRIPTION OF DRAWING(S) - The figure is a cross sectional side view of an advective solar collector.    Elongated light-transmitting roof mechanism (11, 18)    Lower evaporator air duct (15)    Upper condenser air duct (16)    Heat exchange pipe mechanism (35)