Abstract: A buoyant elongated trough-like structure closed throughout an upper portion thereof by means of a transparent panel for passing radiant energy from the sun therethrough is provided and a portion of the interior of the trough below the transparent panel defines an open top compartment for receiving water to be evaporated and subsequently condensed. Lower and upper portions of one wall of the trough include inlet and outlet openings extending along the trough and a hollow U-shaped manifold extends longitudinally of the slotted side wall of the trough and opens toward the latter including a lower hollow leg opening into the interior of the trough through the lower slot and a hollow upper leg opening into the trough through the upper slot. The ends of the legs of the manifold remote from the trough are joined by means of an integral hollow bight portion.

Abstract: A buoyant structure is provided including an upwardly opening solar furnace having a boiler disposed therein and an upper sun ray collecting and concentrating structure at its upper end for collecting and directing rays from the sun incident thereon onto heat transfer and absorbing surfaces of the boiler. The sun ray collecting and concentrating structure is supported above the normal water line of the buoyant structure and the latter supports an exteriorly mounted condenser unit below the water line of the buoyant structure. Air convection lines extend between the boiler and the condenser for the purpose of ducting hot moist air from the boiler into the condenser and cool drier air from the condenser back into the boiler.