The claim that Martians had built irrigation canals on their planet originated in the observations of the famous Italian astronomer Giovanni V. Schiaparelli (1835—1910). As a young man, Schiaparelli studied civil engineering at the University of Turin, where he specialized in architectural and hydraulic engineering. Schiaparelli learned how to design and construct canals, dams, sewers, aqueducts, pipelines, flood control systems, and other structures associated with the flow of fluids.
Despite his early professional training, Schiaparelli never practiced as an engineer. He briefly taught mathematics and then studied astronomy at observatories in Germany and Russia. In 1862 he became director of the Brera observatory in Milan, a post he held with great distinction for thirty-eight years.
Within a month after Hall discovered the two Martian moons, Schiaparelli decided to survey Mars and produce a new map of the planet. In 1877 Martian cartography needed a new naming system for the planet's prominent land formations. Although Schiaparelli promised that his nomenclature would not interfere with "the cold and rigorous observations of facts,"2 the names he chose were not neutral. Schiaparelli designated dark bluish-green areas ofMars as bodies ofwater and lighter reddish-hued areas as land. In renaming the topographical features of Mars, Schiaparelli perpetuated the centuries-old practice of extending features of the terrestrial world into the extraterrestrial.
Of all the Martian landmarks Schiaparelli identified, none were more important than his canali. Canali is an Italian word that deserves special attention because it was translated into English as canals, that is, structures built by intelligent beings. The Oxford English Dictionary defines canal as "An artificial watercourse uniting rivers, lakes, or seas, for purposes of inland navigation, irrigation, or conveyance of water power." The Erie, Suez, and Panama Canals are all artificial waterways. In contrast, the English Channel is a natural waterway.
Unlike the English word canal, the Italian canale (singular) covers both artificial and natural watercourses. The English Channel becomes il Canale della Manica while the Suez Canal is il Canale di Suez. Schiaparelli called the thin dark lines he observed on Mars canali di Marte (canals of Mars). The ambiguity inherent in the Italian canale reflected Schiaparelli's own ambiguous response to what he saw in his telescope. Were canali artificial or natural? If they were artificial, this meant that Martian engineers were able to build and maintain an extensive system of waterways.
Schiaparelli observed il canali di Marte in 1877. Eight years earlier, il Canale di Suez had opened to oceanic ship traffic for the first time. The completion of the Suez Canal was an event celebrated throughout Europe and the Near East. Notable European and Near Eastern diplomats and political leaders were on hand for the occasion, and the Italian composer Giuseppe Verdi wrote the opera Aida to commemorate the canal's opening.
Schiaparelli, who had studied water-control engineering, was undoubtedly impressed by the construction of a waterway through the Egyptian desert. The Suez Canal ran for 103 miles, the longest ship canal in the world. It was called the greatest accomplishment of civil engineering in history.
The success of the Suez Canal stimulated large-ship canal construction around the globe. The great age of the ship canal coincided with a heightened interest in canals on Mars. As we will see, Martians did not build canals for inland navigation. The canals on Mars brought irrigation water to dry regions of the planet. Nevertheless, terrestrial and Martian canals represented the highest technological achievement of their respective cultures.
Schiaparelli was not the first to view or name the canal-like markings on the Martian landscape. Nevertheless, he went far beyond his predecessors in the extent and accuracy of his observations, the detailed precision of his maps of Mars, and the claim that the canali formed a complex network. He reinforced the idea of a wet Mars by emphasizing the presence of canali there. Water flowed in canali whether they were natural or artificial channels.
Schiaparelli drew comparisons between watercourses on Mars and the Earth when he interpreted observational data collected in 1877. Since 1830 observers of Mars had drawn a long line that ended in the so-named Solis Lacus (Lake of the Sun), Schiaparelli interpreted the line as a canale that drained its waters into the lake. By 1877 that line had disappeared from the Martian landscape. It had become invisible to observers using the best telescopes.
Schiaparelli had a ready explanation for the disappearance of the line. He wrote that changes in the "hydraulic regime of this region"3 ofMars were similar to alterations the Yellow River in China had undergone recently. The Yellow River's water-control system included dikes, dams, and canals to restrain devastating flood waters and carry water to farm land.
The late nineteenth-century telescopic observations of Mars took place at the threshold of visual perception. Schiaparelli and the astronomers who supported or disputed his canali hypothesis speculated about the meaning of markings they glimpsed intermittently on the face of the planet. Viewings of Mars carried out within moments of one another yielded hand-drawn sketches that differed markedly.
Initially, Schiaparelli used a small 8.6-inch-diameter refractor to observe Mars, although he later moved to larger telescopes. Nineteenth-century astronomers disagreed about the best telescope size for viewing Mars. This debate coincided with questions about the quality of vision of the observer. It was common knowledge that although Schiaparelli was color blind, he studied a planet famous for its varied colored surface. His affliction, however, did not stop him from sketching an intricate web of lines he claimed to see on Mars.
Schiaparelli's interpretation of the markings on Mars as canali won him widespread support, as well as strong criticism. His supporters called him a modern Columbus who had discovered a new world on Mars. His critics challenged his interpretation of the evidence but never questioned his integrity as a scientist or his brilliance and dedication as an astronomical observer. Respect for Schiaparelli's scientific work often led astronomers to overcome their initial skepticism and accept the existence of the canali.
Schiaparelli's 1877 observations of Mars marked the beginning of the study of the planet by modern professional astronomers. His work brought Mars, and planetary astronomy, to the attention of the most skilled and experienced astronomers in Europe, Britain, and the United States. With Schiaparelli's map of Mars in their hands, or at least in their minds, large numbers of astronomers investigated the obscure markings on the planet.
Schiaparelli published a series of maps of Mars based upon observations he made between 1877 and 1890. He approached Martian cartography in the spirit of a civil engineer asked to lay out the plan of a building site on a plot of land or map a terrain. His maps were notable on two counts. First, Schiaparelli drew them with great precision. He approached the mapping of Martian canali as an exercise in the triangulation of the prominent surface features he observed. His survey of Mars included sixty-two fundamental points plotted with the aid of a micrometer. Schiaparelli's obsession with precise measurement gained him respect for thoroughness. It also raised the complaint that his "micrometric vision"4 distorted his maps.
Schiaparelli's micrometric vision contributed to the second, and more controversial, aspect of his mapping ofMars. Critics often mentioned the diagrammatic and geometrical character of his maps. Schiaparelli boasted that his canali appeared to have been drawn using a ruler or compass. His critics charged that this precision was a result of the prior notions he brought to mapping Mars. He drew a scheme or diagram of the Martian surface that highlighted geometrical forms above all else. Schiaparelli's charts were more like engineering drawings than maps of a complex planetary surface viewed at a great distance under difficult conditions.
Schiaparelli never fully overcame his engineering education. He combined the technician's need for precision with the civil engineer's geometrical world view. His maps of Mars were bold and clear. They depicted canali that interconnected to form a planetwide hydrographic system. This system included canali that were 75 miles wide and 3,000 miles long (Fig. 4.2).
Schiaparelli and the English astronomer Nathaniel E. Greene both observed Mars in 1877. Shortly thereafter, each published detailed maps of the planet. Using a thirteen-inch-diameter reflector, Greene studied the planet from a favorable location on the island of Madeira. Greene's viewing conditions were excellent, and his telescope had a larger diameter than did Schiaparelli's. Greene produced a delicately shaded map filled with subtle distinctions ofline and form. Greene's map showed no canali (Fig. 4.3). How could two expert observers study Mars at approximately the same time and produce different results?
Greene was not only an astronomer. He was a trained artist who had instructed the English royal family, including Queen Victoria, in the art of painting. The Reverend T. E. Webb, who evaluated the two maps in 1879, called
Greene's effort a picture, or portrait, of Mars, and Schiaparelli's a carefully plotted and sharply outlined chart. In his review of Schiaparelli's map, Webb delicately reminded his readers that the Italian astronomer's vision was hampered by color blindness.
Greene attributed the hard and sharp lines of Schiaparelli's map to his drawing technique. The English astronomer suggested that either Schiaparelli's eye, or the eyepiece of his telescope, had a tendency to join a series of separate dots into the straight line of a canale. Schiaparelli responded that it was as impossible to doubt the existence of the canali as it was to question the reality of the Rhine River.
Shortly after publication of his map of Mars, Schiaparelli made a startling discovery. The canali were undergoing a process of "gemination" or doubling. Where at one time there was a single dark line, now there were two. The second line was parallel and equal in length to the original and set apart from it a distance of 210 to 420 miles. By 1882 twenty of the sixty canali Schiaparelli observed had doubled (Fig. 4.4). He concluded that gemination was not an optical illusion. He was absolutely certain he had observed a novel event on Mars.
Schiaparelli's latest observations brought new attention to the red planet. The level of controversy surrounding Mars rose as the number of astronomers searching for canals increased. Only a few observers were able to verify the process of gemination. Those who opposed Schiaparelli's canali hypothesis argued that the lines were not doubling. They said that the Italian astronomer suffered from eye fatigue. He was seeing double.
The canali debate stimulated the imagination of astronomers. An English observer reported that gemination was an optical effect produced by mists hanging over Martian rivers at certain times of the year. A respected French astronomer announced that waters from an adjacent sea had recently inundated the huge Martian continent of Libya and that a canal ran directly across the northern Martian sea. The American astronomer William H. Pickering argued that the observed duplication of lines was due to variations in plant growth along the canals.
Any respect William Pickering gained from his vegetative theory of gemination he soon lost in Peru. In 1892 his brother Edward C. Pickering, director of the Harvard observatory, sent William to Peru to photograph stars and nebula. Instead of following his brother's instructions, William turned his telescope on Mars and telegraphed home that he had witnessed a Martian snowstorm as well as the melting of the accumulated snow. Sensational discoveries from Peru continued to mount, and Edward Pickering finally relieved his brother of his post.
As claims and counterclaims about the canali spread in the 1890s, the scientific dispute reached the general public. The dispute was picked up by science popularizers, writers of fiction, and sensationalist journalists. Interest in Martian canali reached such a peak in those years that a historian has likened the Martian canal furor to mass hysteria.
Martian canali emerged from scientific literature but soon entered a fantasy world of unbridled speculation. This included claims that intelligent Martians had built enormous structures on the planet, sent light signals, and made plans to invade the Earth. Inventors Thomas Edison, Nicola Tesla, and Guglielmo Marconi gave credibility to claims of Martian signals when they offered their technical advice to facilitate radio communication between the Earth and Mars.
The ambiguities of the Italian word canali cannot be blamed on Schiaparelli. The word originally referred to both natural and artificial watercourses. However, Schiaparelli exploited the double meaning of the word. If canali of any sort existed on Mars, that meant that there was water on the planet. Furthermore, Schiaparelli repeatedly drew canali as perfectly straight lines extending for hundreds of miles. He knew that only structures designed and executed by intelligent beings appear as if drawn onto the landscape with a straight-edge.
Schiaparelli saw himself as a disinterested observer, a dedicated collector of facts. His books, maps, and essays tell us otherwise. Schiaparelli's interpretation and visualization of the facts he gathered supported his deeper belief that creatures capable of completing great technological projects lived on Mars.
A year before his death in 1910, Schiaparelli confided to a friend that his eyesight had been deteriorating since 1890. Hence, he decided not to publish the results of any observations made after that year. However, Schiaparelli maintained an interest in Martian canali to the end of his life. His self-imposed ban on publication did not extend to general essays about the nature of canali. In 1893 and 1895, he published two articles in which he discussed the possibility and nature of intelligent life on Mars.
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