Stone Spheres of Costa Rica
by Robin Miller.
- 1 What are the Stone Spheres?
- 2 Context
- 3 Pseudoarchaeological Narrative
- 4 References
What are the Stone Spheres?
Each stone sphere is carved from a hard igneous rock. Most of the spheres have diameters ranging from 60 and 120 centimetres. However, some are significantly larger, with diameters of 170 centimetres, and the largest known sphere has a diameter of 257 centimeters and weighs 15 tons. Most of the stone spheres have been found in the Diquis Delta, which is in the southern Pacific region of Costa Rica. Within the Diquis Delta, many of the spheres come from a few sites in a banana plantation in the Sierpe-Térraba Delta. However, there are a number of other sites containing spheres in that part of Costa Rica, and spheres have been documented in at least one site in Panama. The spheres have been found with artifacts which suggest that they were made between A.D. 400 and 800. 
One of the first people to describe the stones formerly was Samuel Lothrop. However, he was not the first person to discover the spheres. He learned of their existence through an acquaintance who told him that the spheres were uncovered at a banana plantation owned by the United Fruit Company in the Diquis Delta. These stone spheres were well known in the region already, although they had not been well studied. Lothrop's wife, who accompanied him when he began investigating the spheres, said that "next door was the house of the company manager, and beyond it a public park. In the exact center of the park was a perfectly rounded sphere about three feet in diameter" . The spheres are fairly common in that region. Lothrop's wife guessed that Lothrop found "60-odd ball in their original locals" during his initial investigations. Today, at least 176 balls are known to exist in the region .
Samuel (Sam) Lothrop
Samuel Kirkland Lothrop (1892 - 1965)  was a fascinating character, and was in some ways a transition from the earlier "India Jones" style of archaeologist to more modern, formal archaeology. He is credited with contributing significantly to many museum collections. Often this took the form of formal archaeological investigations, but occasionally to he would use other, less orthodox methods. For example, at one point he apparently concluded that he could not prevent a group of amateur pot hunters from operating, and instead became involved in their organization and helped them transition to a "respectable and responsible archeological society" . He grew up in Massachusetts and Porta Rico, and graduated from Harvard in 1915. He served in World War I as a Second Lieutenant in United States Army Military Intelligence, and received his PhD from Harvard in 1921. 
Condition Of the Spheres
Many of the stone spheres have been damaged both by human interference and by natural processes. Local legends of gold attracted the interest of looters who would disrupted many of the sites in the area, include those which contained spheres. Occasionally, these individuals would damage the spheres themselves in the hope that gold artifacts might be found inside them. These looters chipped at the exteriors of the spheres and sometimes split them open with dynamite.
Many of these disruptions had already occurred when the spheres were described by Samuel Lothrop. His wife said that "there were also great chunks of rock, the remains of balls that superstitious natives had blasted to bits in the belief that they might contain gold" . Additionally, the spheres have been used extensively by the modern inhabitants of the region as lawn ornaments. This practice was also already occurring when Lothrop made his descriptions  and is still common today  . Finally, since many of the spheres were never buried, they have been eroded by rain and other natural processes.
The spheres would have been time consuming and difficult to produce, likely requiring a significant investment of collective labor. They are carved a local igneous rock called granodiorite which is very hard . Thus, the artisans who built them probably used repeated heating and cooling cycles to weaken the rock  , which is known to cause granodiorite to "exfoliate in layers" . These heating and cooling cycles may have been achieved by alternating between heating the spheres with hot coals to cooling them with water. This would have required an extensive and advanced knowledge of stone working and behavior. The artisans also probably used measuring sticks to ensure that the balls reached nearly spherical dimensions. In addition to heating and cooling, hammers, chisels would also have been used, and the spheres would have then been polished  . Similar processes were used to make other stone products, such as axes and other tools .
Some of the spheres are quite large, and these would have been difficult to transport, especially given the the dense local vegetation and intense rainy season. They were likely moved using levers and may have required felling trees and the placement of paving stones in ordered to transport them. This would also have required large groups of workers to accomplish. 
The spheres were built by Chibchan speakers. They have generally been found in preserved static settlements. These settlements were fairly developed, but were dispersed and generally did not have more than 2000 inhabitants . The were characterized by paved roads and homes with stone foundations . It appears that the spheres were often placed in public places, such as plazas, for display. Also, the spheres have been found in both large and small settlements. While some spheres stood alone, many were placed in geometric patterns . The spheres were often associated with other objects, such as smaller "peg-base" anthropomorphic sculptures and ceramic pottery fragments. They were also sometimes found with metallurgical artifacts, especially gold and copper artifacts. The "peg-base" statues are particularly interesting, because, like the stone spheres, they are fairly unique to the Diquis region. 
The culture which constructed the spheres was a strongly hierarchical society, characterized by a stratified social structure. These social structure was not unique the people who built the spheres, with similar hierarchical structures appearing throughout the region. The spheres are believed to have been "power symbols", which would have been used to indicate social standing .
While it is true that most of the spheres appear to have been placed in public, this may not have been the case for all the balls. Some were placed in fields outside of the local villages and towns. There are also some reports, most notably by Lothrop, that at least two of spheres were found in burials, along with other ceramic and metalic objects. However, he discovered this when he observed the burials being plundered by treasure hunters, so his report contained somewhat limited information and not all of the associated artifacts have been recovered .
The Diquis Delta is not the only area in the region with monumental architecture, however. Another pair of sites in the nearby San Jose Province are known to contain significant monumental constructions dating to the Chiriqui archaeological phase. These sites are characterized by large stone structures in which houses were surrounded by large rings of paving stones. 
Atlantis In America
Ivar Zapp and George Erikson are responsible for most of the pseudoarchaeological interest in the spheres . In their book, Atlantis In America, they present an argument to the effect that the spheres represent evidence of Atlantian presence in South America, and the Americas in general . They believe that the spheres were part a Atlantian navigational school, teaching its students how to "navigate both the heavens and the seas" .
Perfection of the Spheres
Zapp and Erikson claim that the artifacts are perfectly spherical. They define this as "having the same diameter and circumference when measured from any point on the sphere"  to a tolerance of better than a few hundredths of an inch . They argue that would have been impossible for local population to manufacture the "perfect" spheres, claiming that Lothrop's investigations found nothing to suggest that local groups could have manufactured the spheres. Thus, Zapp and Erikson reason that the spheres could only have been built by a group of people with advanced technology.
However, the artifacts are not perfectly spherical. The spheres are known to be imperfect, and in any case erosion has damaged many of the spheres too much to be meaningfully measured. Erkison and Zapp cite Lothrop's original description of the spheres. However, according to his wife - who accompanied in the field him as he took the measurements - he was unable to excavate many of the larger spheres, and thus had to using a plumb and line.   He also used a tap measure to measure accessible circumferences, and estimated diameters from those. . However, neither of these methods was particularly precise, and so Lothrop took averages in his paper, which reported higher precision than he was actually able to measure .
Size of the Spheres
The authors of Atlantis in America describe the artifacts as "great spheres, some measuring over nine feet in diameter, and later found to weigh as much as twenty tons" . In a second article, apparently regarding the book, George Erikson says that "spheres seven feet in diameter and weighing over 30 tons have been found to be within 2 millimeters of absolute spherical perfection" . Even if these statements were not self contradicting, the fact remains that the largest known sphere weighs only 16 tons and has a diameter of around 2.5 meters, or about eight feet.
Geometrical Placements and Alignments
The spheres are often found in groups, placed in geometric patterns, which were sometimes aligned with the cardinal directions . Ivar Zapp was aware of this, and it became an important part of his thesis. He by casting lines through pairs of spheres in several of these groups, he was able to synthesize links to other significant archaeological sites - such as Stonehenge, the Great Pyramid at Giza and Easter Island - which he believed were related to Atlantis. These intersections then form the basis of an argument that the Costa Ricans were in fact an advanced sea faring civilization, and these geometric patterns of spheres were used as part of ancient university for teaching navigation .
However, other scholars have pointed out that Zapp's measurements of the placements of the spheres were not very accurate, and this lack of accuracy would have introduced significant error into any line casts that he attempted to make, given the large size of the earth and the distances he was trying to work with . Indeed, Zapp himself admits that, when he attempted to use a Boeing 727's navigation computer to verify his projection line to East Island, it was found to be off by some 70 kilometers. Although he initially found this troubling, he persevered, and was eventually able to dismissed this as insignificant. He suggested that it could be an error on the sphere makers part, arguing that other cultures seafaring cultures such as the phoneticians could have found the islands regardless.  Additionally, many of the spheres have been moved, so much evidence of any alignments, if such ever existed, has been lost. 
At the beginning of the classic Indiana Jones film Indiana Jones and the Raiders of the Lost Arc the hero takes an artefact from a tomb or temple. However, he inadvertently sets off a complex array of booby traps. One of these traps is massive stone sphere set into a system of rails such that the sphere pursue him out the temple.  It has been suggested that sphere in this scene was inspired in part by the Costa Rican Stone Spheres. 
- Hoopes, John W. “Stone Balls of Costa Rica.” Stone Balls of Costa Rica, web.archive.org/web/20130323063029/http://web.ku.edu:80/~hoopes/balls/index.htm.
- Quilter, J., & Hoopes, J. W. (2003). Gold and power in ancient Costa Rica, Panama and Colombia a symposium at Dumbarton Oaks, 9 and 10 October 1999. Washington, D.C.: Dumbarton Oaks Research Library and Collection.
- Eleanor Lothrop, Eleanor. “Prehistoric Stone Balls--a Mystery.” Prehistoric Stone Balls--a Mystery | Natural History Magazine, Natural History Magazine, www.naturalhistorymag.com/picks-from-the-past/191353/prehistoric-stone-balls-a-mystery?page=4.
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- Zapp, Ivar, and George Erikson. Atlantis In America: Navigators Of The Ancient World. Adventures Unlimited Press, 1998.
- Indiana Jones and the raiders of the lost arc. (1981). Hollywood, CA: Paramount.
- Boissoneault , Lorraine. “Objects of Wonder: Costa Rica’s Stone Spheres.” Objects of Wonder: Costa Rica’s Stone Spheres | JSTOR Daily, JSTOR Daily, 14 Jan. 2016, daily.jstor.org/objects-wonder-costa-ricas-stone-spheres/.