Strange Attraction: The Mystery of Magnetism
Some time about the beginning of the period which the archaeologists have called the Barra (1850-1650 B.C.), the people of coastal Soconusco appear to have developed a hierarchical society of sorts, for the construction of large, relatively elaborate houses on elevated, packed earth mounds, apparently intended for the use of chieftains, was already being carried on (Clark, 1991, 13). The rise of an elite which could command the labor and no doubt the tribute of the working masses, even before a large-scale dependence on farming had evolved, suggests that the food supply was relatively secure, that an exchangeable surplus was available -- at least for the favored few -- and that a specialization of labor was under way. Population densities were high enough to imply that village life was commonplace and that a political superstructure, based certainly on genealogy but perhaps increasingly on wealth as well, was in the process of formation. Indeed, the peoples of Barra-phase Soconusco appear to have created the first ranked societies in all of North America.
There is some question as to when the first pottery appeared in Mesoamerica. Ceramic shards found at Puerto Marquez on the west coast of Mexico near Acapulco and dated to 2400 B.C. have recently been challenged by Clark and Gosser (1994, 1). They argue that the sophisticated Barra pottery found in coastal Soconusco represents some of the oldest dependably dated ceramic ware in Mesoamerica, but that two other pottery traditions were also in evidence within the region by 1600 B.C. One of these was in the central highlands of Mexico where Purrón pottery appeared, and the third center was in northern Veracruz where the so-called Chajil pottery has been unearthed. Although it is unclear whether these Mesoamerican complexes developed spontaneously and independently or whether they were influenced by ceramic complexes that are known to have existed in northern South America from one to four millennia earlier, it seems quite apparent that they owed little or no inspiration to each other. For example, whereas Purrón pottery was relatively austere and utilitarian, Barra was elaborately decorated and functionally specialized -- the first typical of everyday housewares, the second of sophisticated luxury goods. Thus, if any conclusion can be drawn regarding the societies which produced these differing types of ceramics it must be that the Purrón, with its rather pedestrian plates, dishes, and cooking bowls, was far less affluent than the Barra, with its ornately slipped and highly burnished drinking goblets. Only with the passage of time did the two styles tend to converge, with the Purrón becoming more "fashionable" and the Barra more utilitarian (Clark and Gosser, 1994, 1-11).
Concurrent with the beginnings of their hierarchical social structure, the people of Soconusco also appear to have begun commemorating the likenesses of their chiefs in monumental sculptures. Not surprisingly, there is considerable difference of opinion among archaeologists regarding the relative age of the sculptures in question. Some contend that they date back to the Early Preclassic (ca. 2000 B.C.), while others assign them to the Late Preclassic (ca. 300 B.C.). Piña Chan, for example, saw them as "pre-Olmec" and dated them to 1200-800 B.C. (1981, 108), whereas Parsons confesses to being "slightly conservative" when assigning them a date about 500 B.C. (1989, 281). Because they can only be dated stratigraphically, it is not always easy to decide with which horizon they should be associated, especially when it is likely -- as some authorities point out -- that the sculptures themselves may have been moved and re-erected in new locations. (The reader is referred to the arguments on this matter presented by John Graham  and A. Demarest .) However, due to the abrupt change in geology along the present Mexico-Guatemala boundary, virtually all such sculptures are found on the Guatemalan side of the line where the local bedrock is basaltic lava, in contrast to the Mexican side where it is granite. Thus, the very nature of the raw materials at hand was responsible for the geographic distribution of this art form, for the granite proved a more challenging and less rewarding material to work with than did the softer and more easily fashioned basalt. Consequently, large rounded boulders, often 1.5 m (5 ft) or more in diameter, were selected as the medium upon which either the rudimentary features of a head or a body were etched out in bas-relief. Only a minimal amount of carving was done, so in all cases the faces have a decidedly bloated appearance and the bodies are corpulent. Indeed, although no aspects of gender are depicted on these statues, archaeologists have called them the "Fat Boys" because of their apparent obesity.
Whether their rotundity is a reflection of the fact that the individuals being depicted were actually fat or whether it was simply a matter of laziness on the part of the sculptor in not carving away more material to make the representation more realistic, we can only speculate. What we do know is that day figurines of obese chieftains were a stock-in-trade among somewhat later artisans farther north in Soconusco (i.e., the Mexican area), so, as in many early cultures, plumpness may well have been considered a sign of beauty and/or affluence (Clark, 1991, 21).
The heads that were depicted tended to have a fairly similar, generic appearance. If they were intended to highlight any individual differences, their sculptors appear to have been singularly unsuccessful, although a few of the heads do have some strikingly unique characteristics. One of them, for example, which is now in front of the little museum at La Democracia, Guatemala, bears a strong likeness to F.D.R., lorgnette eyeglasses and all. The bodies, on the other hand, almost invariably have the arms wrapped around them so the fingers of the hands nearly come together over the fullness of their abdomens, and the legs and feet often do a similar encircling act near the base of the sculpture.
One of the so-called "Fat Boy" sculptures located in the town plaza of La Democracia, Guatemala. Originally unearthed at nearby Monte Alto, it was labeled Monument 5 and is believed by Parsons to date to about 500 B.C. The magnetic properties of these sculptures were first discovered in 1979 by my student assistant, Paul Dunn of the Dartmouth class of 1981.
Despite their crudity as works of "art," the "Fat Boys" have one characteristic which lends them a true air of mystery: Many of them are magnetic! This discovery, made by my field assistant Paul Dunn and myself in 1979, took everyone, including the archaeological community, by complete surprise. If the sculpture depicts a head, it is often magnetic in the right temple. If it depicts a body, its magnetic pole is usually near the navel. However, no plugs of magnetic material have been inserted into the boulders at these points. Rather, at these places the sculptures appear to contain enough of a concentration of magnetite, or magnetic iron ore (Fe304) to attract a compass needle. Moreover, these localized zones of magnetism usually have an opposite pole of attraction situated scarcely more than 10 cm (4 in.) away. Thus, where the magnetic lines of force enter a head above the right ear, they usually leave it below the ear. And if the magnetic lines of force enter a body to the left of the navel, they tend to exit it to the right of the navel. Each sculpture, therefore, usually has two oppositely charged poles situated so closely together as to suggest a kind of U-shaped magnetic field.
Today, eleven of these statues are found in La Democracia, Guatemala, arrayed along two sides of the town's plaza, while the twelfth stands near the entrance to the museum. They reportedly were assembled from the newly cleared sugarcane fields surrounding the village sometime after 1950. Five of the statues depict human bodies, six depict human heads, and one is fashioned in the shape of a large bowl or receptacle. Of the humanoid figures, four of the five bodies have magnetic properties, as do four of the six heads. If we begin on the northwest corner of the plaza, we find the following patterns occurring in a counterclockwise direction:
West side of plaza:
(1) Body; north pole to the left of navel; south pole to the right of navel
(2) Head; north pole in the right temple; south pole below the right ear
(3) Head; no magnetic property discernible
(4) Body; no magnetic property discernible
(5) Head; no magnetic property discernible
(6) Head; north pole in lower right ear
East side of plaza:
(7) Basin or receptacle; no magnetic property discernible
(8) Body; north pole to the left of navel; south pole to the right of navel
(9) Head; strikingly Olmec characteristics; no magnetic property discernible
(10) Body; north pole on upper right side of body near waist; south pole on lower right side of body
(11) Body; north pole in back of head; south pole on back of right side of head
On the front, or east side, of museum:
(12) Head; a line of north polarity occurs along the middle of the nose, mouth, and chin; south pole at the bottom of the right ear
Of course, the enigma posed by the "Fat Boys" is really a double barreled one. First, we must ask if their sculptors were actually aware of their magnetic property, and, if so, how they might have initially recognized it, especially in the presumed absence of iron. Or, on the other hand, might not the localization of magnetic poles within these sculptures have been simply a matter of chance? And second, if the magnetic property of each of these stones was indeed known, what prompted their sculptors to associate this mystical force with such localized parts of the body as the right temple and the navel?
Even if it does not take one magnet to detect another, at least it requires a sensitized piece of iron, such as the needle of a compass, to do so. Greek sources credit Thales of Miletus with having discovered the property of magnetism about 600 B.C., and the Chinese author Fu Chin mentions "a stone which can give a needle its direction" in a manuscript dating from 121 B.C. Yet, the Mesoamerican cultures, to the best of our knowledge, remained innocent of the use of metals until at least as late as the ninth or tenth century of the Christian era. Even then their acquaintance appears to have been limited to such metals as copper, silver, and gold, all of which have a lustrous appearance. Thus, how a Stone Age people familiar with chipping their primary tools and weapons out of materials like flint and obsidian stumbled onto the presence of magnetic iron ore in basalt boulders remains a mystery.
The most likely explanation which suggests itself is that the stone carver or sculptor may have noticed the attraction and/or adhesion of fine dust particles to the surface of the monument as he was cutting and polishing it. Naturally his curiosity would have been aroused as he observed that small fragments of the material he was working on were being drawn back to the stone from which he was trying to remove them. A less likely scenario for the discovery of magnetism might have been the chance placement of two small iron-rich boulders close to one another, causing them either to attract or repel one another depending on their polarity.
Whichever of these hypothetical reconstructions we favor, central to both of them is the notion of a stone carver working with a basalt boulder that is endowed with significant local concentrations of magnetite. Let us assume for the moment that, however the property of magnetism was first discovered in Mesoamerica, it is now known. The question which confronts us next is how and why it ever became associated with the right temple of the head or with the navel. What imaginative belief or line of reasoning impelled a stone carver to shape a carving of a head in such fashion that the magnetic lines of force came to a focus both above and below the figure's right ear? Or, when carving a massively rotund body, to make sure to position his subject in such a way that the magnetic lines of force entered and exited on either side of the figure's navel? Surely the sculptors' conscious repetition of this orientation in statue after statue cannot have been any more a matter of chance than if all the sculptures had been hit by lightning in precisely these same places. Clearly, something in the early Soconuscan culture seems to have dictated a linkage between the right temple and magnetism and between the navel and magnetism. What was it?
Naturally, one might conjecture that the connection being implied between magnetism and the head was the symbolization of a mental or spiritual link -- perhaps the commemoration of creative thought. The fact that the right temple was selected rather than the left may simply have been a reflection of the overwhelming propensity of humankind for right-handedness; surely the ancient Soconuscan stone carver would not have been aware that control over the right side of the body is actually centered in the left hemisphere of the brain. Similarly, the association between magnetism and the navel may well have been a commemoration of the physical side of life -- the continuity of the life-force from mother to child, despite the cutting of the umbilical cord at birth.
Had the "Fat Boys" been the only magnetic sculptures discovered in Soconusco, these speculations may have borne some semblance to the true nature of the thought processes which went through the minds of the ancient stone carvers. But, as luck would have it, the first magnetic sculpture found in the region (by the author at Izapa in southernmost Mexico in 1975) was not a depiction of a human head or body at all, but most likely the representation of the head of a turtle. (At least it was so identified by me and my student assistants, although we later learned that the personnel of the New World Archaeological Foundation who had initially excavated the sculpture had termed it a "frog.") Located some 30 m (100 ft) to the southeast of the ramped pyramid of Group F (on the northwest side of Highway 200), the turtle-head has a strong north polarity in its snout and an equally strong south polarity in the extreme back of its head. In addition, there is a weaker pole of south polarity located on the right side of its mouth directly under its right eye. Overall its magnetic attraction is such that it easily deflects a compass needle from 15 cm (6 in.) away, and the resultant field represents a good approximation of that demonstrated in a classic science-class iron filings experiment. In short, the turtle's head acts as a giant bar magnet.
The earliest magnetic sculpture discovered in Mesoamerica was this carved turtle-head located about 30 m (100 ft) off the main pyramid of Group F at Izapa, identified by the author in 1975. In the inventory of monuments compiled at the site, this was catalogued as A 54.
Once the sculpture's magnetic properties had been identified and measured, I had my students undertake a survey of all the other exposed rock at the site to determine whether this was a unique or commonplace occurrence. When the survey revealed that this was the only magnetic sculpture which could be identified, I felt confident in concluding that its carver must have purposefully reserved this magnetite-rich boulder for his representation of a turtle. But then the question arose -- what could have prompted him to associate magnetism with a turtle?
When I reported this discovery to the scientific community in the journal Nature in February 1976, the editor permitted me one sentence of speculation -- to wit, might the carver have somehow come to associate the uncanny homing instinct of turtles with magnetism? At the time the article was published, such speculation had little supporting evidence to back it up. Indeed, one of the world's most eminent specialists on turtles, Archie Carr of the University of Florida, had only recently completed an intensive investigation of the navigational abilities of this reptile for the Office of Naval Research but was forced to conclude, after testing every conceivable hypothesis, that he still didn't know how they did it; when it came to magnetism, all he could say was that he could not rule it out (Carr, 1967, 171). Of possible relevance to the question at hand, however, was a reference which Carr made to a deep-carapaced black turtle that migrated from the Galápagos Islands to lay its eggs on a limited stretch of black-sand beach in Soconusco. Not only were other species of turtles well known within the region because of the periodic migrations of loggerheads and leathernecks north and south along the shore, but since time immemorial the turtle had served as one of the preferred sources of meat. Although Carr was of necessity cautious and noncommital, recent research in zoology increasingly suggests that not only turtles but also birds and even some worms may orient themselves by using the earth's magnetic lines of force, so what may have been a questionable speculation in 1976 has now become an area for serious inquiry (Seachrist, 1994, 661).
The "Fat Boys" assembled in La Democracia and the turtle-head found at Izapa do not exhaust the examples of magnetic sculptures found in Soconusco, however. Among the assortment of stone carvings brought together in the open-air "museum" at the El Baúl sugar plantation in Guatemala are not only the third-oldest known Long Count inscription (of which more presently) but also at least two statues possessing magnetic properties. One of these (discovered in 1979) depicts two men sitting cross-legged on a bench with their arms crossed on their chests. Both men have north magnetic poles where their arms cross, while under the bench upon which they sit are two south magnetic poles -- the pole below the man on the left, as one faces them, being more pronounced than that beneath the man on the right. Nearby, a well-fashioned likeness of a rampant jaguar was found to have north magnetic poles in both of its paws, but no discernible south poles. (This discovery came to light when another student assistant and I revisited the site in 1993.) Finally, a small humanoid sculpture situated in the plaza of the village of TuxtIa Chica near Izapa was found in 1983 to be magnetic in the right side of its head.
Thus, the mystery of magnetism in Soconusco remains just that: Because the 'Fat Boys" appear to have been the earliest of this collection of carvings, it seems that magnetism, however it was discovered, was first associated with human beings -- at least in the cluster of statues found in the Guatemalan piedmont. Later, and in a different part of Soconusco -- this time just over the present-day border in southern Mexico -- another sculptor fashioned a carving of a turtle's head having a magnetic field focused on its snout. Does this mean that the local appreciation of magnetism had changed, or were the discoveries and associations of magnetism -- first with people and later with the turtle -- independent and unique? One can only continue to speculate. But what does seem certain, however, is that the property of magnetism had been identified in Soconusco, perhaps as early as 2000 B.C., but in any case well before the birth of Christ, and that it had been incorporated into the local statuary.
THE GEOGRAPHIC EXTENT OF THE KNOWLEDGE OF MAGNETISM
Inasmuch as the property of magnetism came to be associated with statuary in Mesoamerica, it appears that the idea of its being useful or practical in any way seems not to have occurred to the native Americans. This may have been because it was never identified in any rock which was portable. Or perhaps it was never appreciated as being more or other than some kind of supernatural or magical force. Clearly, no understanding of its direction-finding properties -- i.e., the principle of a compass -- seems to have resulted from their discovery. However, some investigators have suggested -- not too convincingly, it should be pointed out -- that the alignment and layout of certain pre-Columbian ceremonial centers may have been carried out with such a device (Fuson, 1969, 504). Unfortunately, our knowledge of what the magnetic field was like at any given place on the earth's surface three thousand years ago is so sketchy that it would be hazardous to push such a hypothesis very far, especially in the absence of any kind of compasslike artifacts.
Due to Soconusco's location almost in line with the historic movement of the north magnetic pole, compasses used in the region would have continued to experience a magnetic declination of virtually the same magnitude throughout the last 500-600 years, unlike those used at such a place as London, England. Whether the movement of the pole during prehistoric times followed a similar path is unknown.
In this connection, however, it is interesting to note that the known shift of the north magnetic pole has been from just north of the Russian islands of Novaya Zemlya sometime about the year 1000 to between Spitsbergen and Greenland about 1500 and into the Queen Elizabeth Islands of the Canadian Arctic by about 1900. While this shift represented a major change in declination for residents of the Old World -- from about 15-20º east of north to the same relative distance west of north over roughly a thousand years -- had this movement been viewed from the longitude of Soconusco (i.e., 90º W), it would have been hardly noticeable. In other words, a compass needle would have pointed almost due north throughout that entire time.
Finally, it should be noted that in Michael Coe's excavations at San Lorenzo in the late 1960's, a piece of magnetite measuring about 2.5 cm. (1 in.) in length and a little less than a 0.5 cm (0.25 in.) in cross-section was uncovered, prompting him to envision it as a part of a compass. Testing its direction-finding properties by floating it on a cork mat, Coe noted that it consistently oriented itself to the same point slightly west of magnetic north. More-exhaustive tests (involving the suspension of the magnetite bar on a thread) were later carried out by John Carlson, who reported that the object's orientational ability did not come closer than about 35º to the north magnetic pole (Carlson, 1975, 753). Thus, it could conceivably have been used as a direction-finder, but with scarcely more "preference" for north than for either east or west.
All of the roughly dozen magnetic sculptures which are known from Mesoamerica. are found within the volcanic bedrock zone of piedmont Soconusco. Several other areas of volcanic bedrock exist in Mesoamerica, such as in the Tuxtla Mountains and along the Transverse Volcanic Axis which runs across the center of Mexico from Citlaltépetl (Orizaba) in the east to Volcán Colima in the west; however, in none of them did the local inhabitants recognize the presence of magnetic iron ore as they apparently did in Soconusco. Because magnetism appears always to have been associated with relatively massive stone carvings which could not be easily moved, the knowledge of this force seems never to have diffused beyond the region.
It appears, therefore, that the knowledge of magnetism never really diffused farther than Soconusco, and then only so far as the local bedrock remained basalt. With the possible exception of some localized use having been made of the magnetite bar found by Coe at San Lorenzo, it likewise appears that the potential use of geomagnetism for direction finding was never fully appreciated by the early Mesoamericans. The author's discovery of the magnetic properties of, first the turtle's head at Izapa, and later, the "Fat Boys" of Guatemala, have served little but to add a dimension of "background static" to the whole equation of Mesoamerican intellectual development. This is because, apart from appreciating their awareness of the force, we know neither how they discovered it nor to what use they may have put it. My imaginative speculation that it may somehow have been associated with the homing instinct in the turtle leads me to insert one final footnote in passing: The Chinese, who are generally credited with having been the first culture to appreciate the direction-finding capacity of geomagnetism, use the term "black-turtle rock" as their description for basalt. Moreover, when they began fashioning compasses with which to navigate, many of their earliest models were made in the form of turtles. One hesitates to raise the question of independent invention versus diffusion -- especially over such a vast expanse as the Pacific -- but in any case the similarity or coincidence in thought patterns is rather striking. Thus, with no real answers at hand, we must conclude that, for the Mesoamericans, magnetism probably remained nothing more than an awe-inspiring marvel of nature.