158 AjStnual eepoet Smithsonian institution, 1915. 



a small channel on the top of each side of the box. These channels 

 delivered into larger ones, and thus the distilled water was collected. 

 The plant jdelded 5,000 gallons of pure water per day in summer, i. e., 

 1 pound of water per square foot of glass. Allowing for interest on 

 capital, cost of repairs, etc., the cost of the pure water is said to have 

 been less than one-half penny per gallon. The chief item of expense 

 was the breakage of glass by whirlwinds. Distillation started at 10 

 a. m. and continued to 10 p. m. The maximum temperature of the 

 water in the troughs was 150° F. The total cost of the plant, includ- 

 ing pumps, windmills, and tanks, was $50,000, or Is. Gd. per square 

 foot of glass. 



It is not clear when the solar energy problem first engaged the atten- 

 tion of C. L. A. Tellier, a French refrigerating engineer, but in 1889 

 he published his book, "Elevation des Eaux par la Chaleur Atmos- 

 pherique," in which he gave many drawings and details, and a very 

 full description of his plant. He may have been the first to use the 

 lamellar boiler, but the United States patent No. 230323, of July 20, 

 1880, of MM. Molera and Cebrian, shows that they proposed this form 

 of boiler. The dimensions of each section of Tellier's boiler were 

 3.5 by 1.12 meters. They were made of thin plates of iron, 

 so riveted together as to give them a quilted formation. They 

 were filled with ammonium hydrate, which, he says, when heated 

 by the sun produced gaseous ammonia at a pressure of "several 

 atmospheres." The ammonia gas was used in a small vertical engine, 

 and was then liquefied in a condenser and used again. The boilers Avere 

 fixed in a sloping position so as to " face the sun," and two somewhat 

 fanciful illustrations show them used as roofs of verandas. The 

 boilers were insulated on their lower or shade sides to prevent loss of 

 heat, and were placed in shallow boxes with only one layer of glass to 

 form the cover. He experimented with different colored glass, and 

 found, as might be expected, that colorless glass gave the best results. 

 He also gave complete details of his invention as applied to the manu- 

 facture of ice. With so much detail it is disappointing that the au- 

 thor could not find the results of a single experiment with the plant. 

 In fact, he is not sure whether Tellier ever constructed one. 



In his work La Conquete Pacifique de I'Afrique Occidentale 

 (1890), Tellier discussed social and economical questions, and showed 

 how improvements might be made by rendering the deserts of Africa 

 productive by means of his sun-power plants. 



A. G. Eneas, in the United States, used the popular truncated, 

 cone-shaped reflector, collecting about 700 square feet of solar radia- 

 tion. The w^eight of the reflector was 8,300 poimds. 



The boiler was formed of two concentric steel tubes, the two together 

 being incased in two glass tubes with an air space between them and 

 another air space between the inner glass one and the outer steel tube. 



