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RAIN MAKERS
It is not generally known ... that the question of causing rain by artificial means is no new one.
—ROBERT DECOURCY WARD, “ARTIFICIAL RAIN”
THE quest to control nature, including the sky, is deeply rooted in the history of Western science. In the dedication to The Great Instauration (1620), Sir Francis Bacon (1561–1626) encouraged his “wisest and most learned” patron, James I, to regenerate and restore the sciences. Bacon’s program involved “collecting and perfecting” natural and experimental histories to ground philosophy and the sciences “on the solid foundation of experience of every kind.”1 His wide-ranging catalog of particular histories included aerial and oceanic topics that are relevant here: lightning, wind, clouds, showers, snow, fog, floods, heat, drought, ebb and flow of the sea. The goal was to replace Aristotelian natural philosophy, stimulate rapid progress in science, improve the human condition through technology, and eventually control nature.
Bacon’s philosophy identified three fundamental states of nature: (1) the liberty of nature, (2) the bonds of nature, and (3) things artificial. In the first category, nature is, well, “natural”—free and unconstrained. The second category comprises mistakes and monstrosities resulting from motions that are violently forced or impeded. The third category involves art and technology—mechanisms and experiments constraining nature to operate under human control. Thus gentle rains falling from the sky may water a garden naturally; rainmaking, which seeks to bond and bend natural processes, is a violent or forced act, a monstrosity; and designed irrigation systems, employed by many agriculturalists, constitute artifice. To cite another example of the three states, a shade tree and a gentle breeze may provide some respite on a hot day; towing icebergs to lower latitudes or turning the blue sky milky white with sulfate aerosols to attenuate sunbeams, however, would be violent acts involving forced motions and would constitute errors of potentially monstrous proportions; and the design of building ventilation and cooling systems, subject to individual choice, is clearly within the realm of artifice. As a third example, the eruption of a volcano is considered a force of nature; making an artificial volcano or otherwise tinkering with an existing one would certainly be a mistake; but deflecting lava flows around a village is an artificial but useful thing to do.
In New Atlantis (1624), the scientists of Solomon’s House practice both observation and manipulation of the weather: “We have high towers ... for the view of divers meteors—as winds, rain, snow, hail, and some of the fiery meteors also. And upon them in some places are dwellings of hermits, whom we visit sometimes and instruct what to observe ... and engines for multiplying and enforcing of winds to set also on divers motions.”2 In great experimental spaces, researchers imitate and demonstrate natural meteors such as snow, hail, rain, thunder, and lightning and “some artificial rains of bodies and not of water” (400). Three so-called mystery men are in charge of expanding the repertoire of practices not yet brought into the arts, and three pioneers or miners try new experiments “such as themselves think good” (410); that is, they manipulate nature without further review or oversight, a task requiring perfect virtue and judgment by the experimentalists.
Bacon was conversant with a venerable humanistic tradition that divided history into three parts—ancient, medieval, and modern—but his valuation of the three eras was asymmetric. He granted grudging respect to the ancients, denigrated the Middle Ages, and elevated modern accomplishments to equal or soon-to-be-greater status than those of antiquity. For Bacon, the rise of modern science was due to “the true method of experience ... commencing ... with experience duly ordered and digested, not bungling or erratic, and from it educing axioms, and from established axioms, again new experiments.”3 “New discoveries,” Bacon argued, “must be sought from the light of nature, not fetched back out of the darkness of antiquity” (154). He elaborated at length on his new method, calling for researchers to work together and making the important point that the sciences were about to enter a period of great fertility. Bacon’s communitarian campaign was taken over by innumerable practitioners in the seventeenth century. His greatest legacy, without doubt, was institutional, in that his outlook was absorbed by the Royal Society of London and by many other scientific societies.
Scientific Revolutions “de l’air”
The “scientific revolution,” although subject to intense historiographic debate, is a term that commonly refers to the transformation of thought about nature through which the authority of ancient texts was replaced by the “mechanical philosophy” and methodology of modern science. Most, but not all, historians see it as a series of events in the sixteenth and seventeenth centuries or, more narrowly, from 1543 (De Revolutionibus of Copernicus) to 1687 (Principia of Newton). The standard accounts privilege astronomy, physics, and medicine, but also in this era natural philosophers turned away from the traditional practice of preparing commentaries on Aristotle’s Meteorologica and instead began focusing on new techniques for describing, measuring, and weighing the atmosphere. Behind this turn was the hope that somehow quantification might lead to understanding and trigger a cascade of new capabilities, including prediction and control. Beginning with the Accademia del Cimento in Florence, the scientific societies of Europe attempted to make histories of the weather and promoted the collection, compilation, dissemination, and discussion of meteorological observations from remote locations and over widespread areas of the globe. Adherents of the new mechanical and chemical philosophy insisted that all atmospheric phenomena could be reduced to their component processes and could be explained by an emerging body of natural laws. They developed new instruments—thermometers, barometers, hygrometers, and calibrated rain gauges—for observing and quantifying aspects of the atmosphere. New practices and perspectives meant that henceforth no atmospheric process, however seemingly insignificant, would be left unrecorded. As a result, a culture of measurement emerged, linked to a new meteorological science of planetary proportions. This “descent, with variation,” of viable meteorological instruments, so proudly traced by scientists and historians, is only one aspect of the story, since many techniques resulted in dead ends—in extinct or forgotten practices. The lack of uniform standards and global and temporal coverage, however, remained a continuing challenge.4
In 1949 one of the early champions of the idea of a scientific revolution, the historian Herbert Butterfield, wrote the following:
Since the Scientific Revolution overturned the authority in science not only of the middle ages but of the ancient world—since it ended not only in the eclipse of scholastic philosophy but in the destruction of Aristotelian physics—it outshines everything since the rise of Christianity and reduces the Renaissance and Reformation to the realm of mere episodes, mere internal displacements, within the system of medieval Christendom. Since it changed the character of habitual mental operations even in the conduct of the non-material sciences, while transforming the whole diagram of the physical universe and the very texture of human life itself, it looms so large as the real origin both of the modern world and of the modern mentality that our customary periodization of European history has become an anachronism and an encumbrance.5
More recently, a prominent feminist scholar, Carolyn Merchant, saw the same events as a disaster of unmitigated proportions: “The removal of animistic, organic assumptions about the cosmos constituted the death of nature—the most far-reaching effect of the Scientific Revolution.”6 She argured that because scientists had redefined nature as a system of dead, inert particles moved by external rather than inherent forces, their endorsement of the reductionistic framework of the mechanical philosophy legitimized nature’s manipulation and progressive destruction. Power over nature was fully compatible with the values of scientists’ ultimate supporters—governments—especially the military establishment, commodifiers, and other ideologues and opportunists of various stripes. Others wonder if there have been many scientific revolutions, or
perhaps none at all!7
Most historians agree that since the seventeenth century, scientists have attempted to complete the Baconian program, elevating the attainment of natural knowledge to the sine qua non of human achievement, and then wielding this knowledge to gain power over and control of nature for the stated purpose of improving the human condition, however narrowly defined, but often falling short of this goal. This program, the opening wedge of a revolution articulated in different ways by Galileo, Descartes, and others, was more than a new set of techniques in the laboratory or the field. It was a revolution in thought that placed humanity at the conceptual and willful center of the universe, redefined our relationship with the natural world, elevated the scientific method to the pinnacle of truth recently vacated by the church fathers, and dealt a blow to apocalyptic thinking. As the Enlightenment eroded belief in divine providence as a moving force in history, the historiographic void was filled by the notion of progress, a secular notion based on the development and application of human reason to the challenges of understanding, prediction, and ultimately, control.
Great Fires and Artificial Volcanoes
In the closing decades of the eighteenth century in Europe, and slightly later in Russia and the United States, serious attempts were made to broaden the geographic coverage of weather observations, standardize their collection, and publish the results. Individual observers in particular locales dutifully tended to their journals while networks of cooperative observers gradually extended the meteorological frontiers. No one, however, had yet proposed a serious scientificbased program of weather control. James Pollard Espy (1785–1860) was a leading meteorologist of his day, the first to be employed by the U.S. government in this capacity. Born into a farm family in Washington County, Pennsylvania, and educated at Transylvania University in Kentucky, he worked as a frontier schoolmaster and lawyer until he moved to Philadelphia in 1817. There he supported himself by teaching mathematics and classics part time at the Franklin Institute while devoting his free time to meteorological research. From 1834 to 1838, he served as the chairman of the Joint Committee on Meteorology of the Franklin Institute and the American Philosophical Society. He won the latter’s Magellenic Prize in 1836 for his theory of hail. Working with the scientific societies of Philadelphia, Espy gained the support of Pennsylvania’s legislature to equip weather observers in each county in the state with barometers, thermometers, and other standard instruments to provide a larger, synoptic view of the weather, especially the passage of storms. He also maintained a national network of correspondents and volunteer observers. During this period, he invented a “nephelescope,” an early cloud chamber, which he used in his popular lectures and, in his technical work, to calculate the amount of heat released by condensing water vapor.
Espy moved to Washington, D.C., in 1842. In his first government appointment, as professor of mathematics in the navy, he developed a ventilator for ships and expanded his network of meteorological correspondents. He also held a joint appointment as the “national meteorologist” in the U.S. Army Medical Department, a position that boosted his storm studies by providing him access to the meteorological reports of the army post surgeons. From 1847 to 1857, his salary was provided by annual appropriations from Congress. With Joseph Henry, he established the Smithsonian meteorological system of observers and experimented with telegraphic weather reports. Several of his major reports on meteorology appeared as U.S. Senate executive documents.8
Espy viewed the atmosphere as a giant heat engine. According to his thermal theory of storms, all atmospheric disturbances, including thunderstorms, hurricanes, and winter storms, are driven by steam power. Heated by the Sun, a column of moist air rises, allowing the surrounding air to rush in. As the heated air ascends, it cools and its moisture condenses, releasing its latent heat (this is the “steam power”) and producing rain, hail, or snow. Espy emphasized, correctly, the importance of knowing the quantity of vapor in the air, “for it is from the latent caloric [or heat] contained in the vapor that all the force of the wind in storms is derived. It is only when the dew-point is high that there is sufficient steam power in the air to produce a violent storm; for all storms are produced by steam power.”9 His theory was well received by many scientists of his time, including a committee of the French Academy of Sciences chaired by François Arago. The convective theory is now an accepted part of meteorology, and for this discovery Espy is well regarded in the history of science.
Espy strayed from the scientific mainstream when he promoted his idea that significant rains of commercial importance for agriculture and navigation could be generated by cutting and burning vast tracts of forest. He believed the heat and smoke from these fires would create huge columns of hot air, producing clouds and triggering precipitation, much like the effects of volcanic eruptions. He listed five scientific reasons why setting large fires should produce rain: (1) experiments showed that expanding air cools dramatically, and (2) under certain conditions of high humidity forms both a visible cloud and significant amounts of precipitation; (3) chemical principles indicated that the “caloric of elasticity” (a venerable term for latent heat) released in the condensation of this vapor is immense, equal to about 20,000 tons of anthracite coal burned on each square mile of cloud extent. Espy’s convective theory further held that (4) this release of heat would keep the cloud buoyant, lower the barometer, and “cause the air to rush inward on all sides toward the center of the cloud and upward in the middle, thus continuing the process of condensation of vapor, formation of cloud, and generation of rain.”10 Espy derived his final point empirically by collecting observations and testimonials to the effect that (5) air does indeed rush inward on all sides toward the center of the region where a great rain is falling and upward into the cloud.
Espy explained that three things can prevent rains from accompanying great fires: (1) winds, (2) excessive moisture, and (3) stability of the upper levels of the atmosphere. He released small balloons and tracked their flight in order to get a sense of the winds, and he used a hygrometer to measure atmospheric moisture and estimate its changes with height. Stability was more of a problem, for as he observed, in the present state of science, the levity of an upper stratum of air could not always be known. Correspondents, friends, and even a congressman laughed at Espy when they heard of his proposal to make rain, but he assured them that science was on his side. He even ventured a prediction of how the experiments might turn out in favorable conditions and felt there was no disgrace in desiring to see a great experiment made. He anticipated that his labors would be crowned with success.
In 1838 Espy petitioned the U.S. Senate to reward him in proportion to his ability to make rain by burning woodlands. James Buchanan (D-Pennsylvania) apologized to his colleagues for the “strange petition” he was about to present, but assured them that it came from “a very respectable and scientific man” with excellent references and credentials:
The petitioner ... says that he has discovered a means of making it rain in a tract of country at a period of time when there would be no rain without the use of his process. Mr. Espy proposed to make the experiment at his own expense; and he proposed that Congress should pass an act engaging to reward him with a certain sum if he succeeded in making it rain in a tract of country ten miles square; a still higher sum if he produced rain in a tract of country one thousand square miles; a still higher sum if he produced rain in a tract of five thousand square miles; and, lastly, to give him a still greater compensation if he should cause the Ohio river to be navigable all summer from Pittsburgh to the Mississippi.11
Buchanan supported the petition based on Espy’s scientific reputation, but “scarcely knew himself what to say about it.” Senator John J. Crittenden (W-Kentucky) “doubted very much, whether, even if this thing was possible, it would be a good policy to encourage the measure.” He thought that no mortal should have the power that Espy professed to have and no one could take the Ohio River under his special protection:
The senators, obviously enjoying the discussion, pointed out that no citizen should be empowered to hoard up the clouds and vapors or to dispense them at will. Buchanan’s motion failed, and Espy’s petition lay on the table. That year, and for several years following, Espy looked closer to home, seeking, but failing to receive, government support for rainmaking. “Magnificent Humbug” opined the Genesee Farmer. According to the Boston Quarterly Review, “The public at large think of him as a sort of madman, who fancies that he can produce artificial rain.”12
Espy’s magnum opus, The Philosophy of Storms (1841), includes a long section titled “Artificial Rains,” in which he compiled testimonies of rainfalls accompanying volcanic eruptions and large fires: “The documents which I have collected on this subject, if they do not prove that the experiment will succeed, do at least prove that it ought to be tried.”13 Espy concluded that if a large body of air is forced to ascend in a column, a large self-sustaining cloud will be generated and cause more air to rise up into it to form more cloud and rain. He argued that this was certainly the case in volcanic eruptions and should also be the case for great fires. He cited the mysterious connection between volcanoes and rain as noted by the famous geographer and explorer Alexander von Humboldt, who observed that sometimes during a volcanic eruption a dry season changed into a rainy one. Thus he argued that the rainmaking effects of a giant forest fire should mimic those of a volcanic eruption.
Fixing the Sky Page 8