An apparatus for obtaining fresh water, Antofagasta. Halftone.

1 process print : halftone ; image 14.1 x 22.8 cm

The balloon as spy, and the sun as water-sweetener. Obtaining fresh water in a nitrate country: a use for the sun in a rainless land. The oquete Nitrate Company, Antofagasta, Chili, which has its works in a rainless country where the sun shines continually, uses an ingenious apparatus for turning the brackish water of the region into sweet water. It consists of a series of frames containing twenty thousand square feet of glass. The panes of glass are arranged in the shape of a V, and under each pane is a shallow pan containing brackish water. The heat of the sun condenses the water upon the sloping glass, and this fresh water then runs down into a little channel, and is carried away into the main canal. Nine hundred and fifty gallons of fresh water can be collected daily.

Wellcome Collection 37818i