The Net Advance of Physics RETRO:
SOLAR ENERGY: Plus ça change ...

2012 November 5

"The day has come when men of hard sense and purely business habits may take up this subject, with no danger of being called visionary." So writes Rev. Charles H. Pope of solar technology in his pamphlet Solar Enginery. The year is 1883.

"The use of sun-heat is to-day exactly where the art of steam-enginery was on that October morning when Fulton set sail up the Hudson, in the year 1807," Pope continues with unshakable optimism.

Pope is a New Englander, but his concern is with the Western frontier, "millions of square miles of land, now practically desert". It is not the prevailing dryness which prevents agriculture and settlement, he argues; after all, vast aquifers sit below the desolation. To tap them would require merely (and here he switches to boldface type) "Engines Which Need No Fuel."

No fuel? No fossil fuel, at least, and no firewood. The very excess of sunlight which scorches the West into a wasteland could be tapped to make the desert a Garden of Eden: "And the sun's force is the hope of all that Western world."

Optics is a popular hobby in the 1800s, its extension to high temperatures a research area. Writing of himself in the third person, Pope describes an experiment:

"Then turning to reflectors, he was struck by the perfection with which the light of a lamp is reflected in parallel lines by locomotive headlights. 'What will fetch will carry,' thought he. So he borrowed one of these reflectors, set it up on a rude frame in his back yard; placed a tube of galvanized iron plate in the place made for the lamp; and had the delight of seeing a quart of water boil in five minutes."

Pope is no professional engineer. His little book is not an account of his own experiments (many of which, as he admits, had been done by others long before) but an appeal for researchers with better qualifications to turn their attention to the new field he calls "solarics".

To establish the respectability of his subject, he reviews the literature. The legendary weapon of Archimedes makes its obligatory appearance, as does Buffon's attempt to recreate it. "I have not been able to discover any application for a patent on any sun-utilizing machine earlier than [that of Antoine Poncon in] the year 1854," he writes, before turning to the work of a French mathematician whose giant "marmites" are today steampunk icons. "It must be acknowledged," Pope writes of this pioneer, whose book La Chaleur Solaire et ses Applications Industrielles appeared in 1869, "that

Augustin Bernard Mouchot

is to be ranked with Watt, Stephenson, Fulton, Morse, Bell, and their like ... though Yankee ingenuity may some day make machines as far superior to his as the latest trans-Atlantic steamship is to that in which Fulton made his first voyage."

Pope continues through the various heroes of "solarics": Ericsson, Adams ... "How many others have helped forward this work quien sabe ?" He discusses stationary devices and devices with tracking; different mirror geometries; different types of reflective coating ("lime or gypsum 'whitewash' having surprising value"). Many of these issues are addressed in more detail in the longer sequel to this pamphlet, Solar Heat, published in 1903.

Technical issues remain, Pope admits, but they are relatively minor, especially when compared to the urgency of progress: "Considering the rapid diminishing of our forests and the tremendous drafts now making on our coal fields, we ought lose no time in availing ourselves of this most freely offered and cheaply available resource; since it has been absolutely proved that it is wholly practicable, and wants only the touch of that manufacturing energy which distinguishes our country."

Wants it still, in 2012.

(See also the Net Advance RETRO Nineteenth-Century solar power page.)