Explorations and field-work of the Smithsonian Institution in .. . Fig. I.—Abbots solar cooker employed on Alount Wilson during summerexpeditions since 1920. was raised to pressures exceeding 100 lbs. per square inch, and usedto drive a small steam engine for exhibition purposes. On one occa-sion, with the cooperation of the National Broadcasting Company, ashort conversation was broadcast by solar power. Although this installation had much promise and some interestingperformance, and although as regards the collection of solar radiationand the absorption of it to produce heat, and even the pre
Explorations and field-work of the Smithsonian Institution in .. . Fig. I.—Abbots solar cooker employed on Alount Wilson during summerexpeditions since 1920. was raised to pressures exceeding 100 lbs. per square inch, and usedto drive a small steam engine for exhibition purposes. On one occa-sion, with the cooperation of the National Broadcasting Company, ashort conversation was broadcast by solar power. Although this installation had much promise and some interestingperformance, and although as regards the collection of solar radiationand the absorption of it to produce heat, and even the preservation ofthe heat for useful purposes, the devices were economical and highlyefficient, defects in the machine as a whole became immediately appar-ent. To appreciate them, let us recall: SMITHSONIAN EXPLORATIONS, I936. U o~ ^ •a^ 03 1- 4 SMITHSONIAN INSTITUTION 1. That in the device which was exhibited at Washington themirrors and heater elements rotated together from east toward westeach day, but the boiler was nonrotating. Hence movable joints tightlycontaining the very hot black liquid had to be provided. These werecostly and yet in practice leaked. 2. Several hours were required to get up full steam pressure,owing to the large capacity for heat of the black lic^uid, the metalparts of the tubes and boiler, and the water in the boiler. This ob-jection would be very serious on a half-cloudy day. Though half thesuns energy were available, full steam pressure could never be raisedon such a day. 3. As the black liquid must flow entirely through each focus tube,and the inner glass wall became very hot while the outer one remainedfairly cool, a difficult glass gooseneck device had to be blown intoeach focus tube to allow for differential heat expansion. We shall now see how these three objections may
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectscienti, bookyear1912
