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Monday, September 1, 2014

The Baure's Linked Canoe and Road Transport System

dugout canoes in Baures region, upper Amazon, Bolivia
Contemporary Baure dugout canoes on the upper Amazon in Bolivia. (Click any image to enlarge.) Source.
The Baure people live between the San Martin, San Joaquin, and Negro Rivers -- upper reaches of the Amazon River system -- in northern Bolivia, near Brazil. The region is mostly savanna, cut through by navigable rivers and streams and with many wetlands and lakes. During the 3-5 month rainy season, the flat savanna and pampas grassland is completely covered by water. As the rainy season ends and the water recedes, the land gradually dries out to support agriculture and grazing.

The Baure people now number less than10,000, but when first described by Jesuit missionaries in the sixteenth century, they were more numerous, living in hundreds of towns on slightly elevated sections of land that naturally support patches of forest dotting the otherwise flat landscape. According to archaeologist Clark L. Erickson, each town was ruled by a hereditary chief, and the towns “had large public plazas with a large men's house or temple in the center. Around the plaza were hundreds of houses arranged along streets and wide avenues. Deep defensive moats and tall palisade walls surrounded many settlements.” Between the towns, raised agricultural fields were built up above the floor of the savanna. Altogether, the area was a "densely populated region filled with large, well- organized dispersed settlements."

Between about 2,000 BP and the time of European contact, the Baure built thousands of raised roads between their towns, totalling tens of thousands of linear miles. Radiating like spokes from every town, these roads connected the towns to one another and to surrounding raised-field farms. They were perfectly straight, often 3 (and occasionally as much as 7) miles long, and no more than a meter high – just high enough to raise the road surface above the seasonal floodwaters. Usually 12-15 feet wide, they were occasionally as wide as 60 feet. They were of simple packed earth construction, the material for which was excavated immediately adjacent to the road itself on one or both sides, creating a network of canals alongside each road.

recreation of precolumbian Baure road/canal complex
Roads carrying foot traffic and canals floating dugout canoes worked in parallel in precolumbian Baure culture. Source.
The road-canal system served multiple functions. The roads were, of course, used for communication and trade. Road travel may also have had important ceremonial or social significance, and the roads may have served as property or territorial boundaries. The roads also likely functioned as dikes to keep certain areas dry and/or to maintain stocks of water in others (for fish empoundments, example), and the canals would have been used to control the flow of water for these functions.

The roads themselves were often built in parallel to and relatively close to one another, so that as many as four roads might connect two towns. This was probably redundant for transportation needs, but it makes sense for the purposes of water control, demarcation of land rights, and possibly ceremonial purposes. Lacking any monumental architecture, the Baure may have viewed their roads – the result of large-scale communal effort – as the equivalent of individual municipal monuments, and the vast road-and-canal network might have served that purpose on a culture-wide basis.

Dugout canoes are in use to this day in the Baures region, and it is almost certain that they were used on the canals for transportation in the precolumbian era. Dugouts made possible the movement of larger quantities of agricultural produce and trade goods than could have been efficiently carried by manpower on the roads. (The Baure had no draft animals or wheeled vehicles.) The canals would have retained enough water for canoe travel long after the savannas dried out at the end of the rainy season, and many of them connected to navigable rivers, expanding the transportation network even further and linking the Baure to distant areas in the Amazon system.

Sources:
Pre-Columbian Roads of the Amazon, Clark L. Erickson, from the publication Expedition, published by Penn Museum (date unknown)
Prehispanic Earthworks of the Baures Region of the Bolivian Amazon, Arqueologist Wilma Winkler Verlarde and Dr. Clark L. Erickson, a project of the Instituto Nacional de Arqueologia de Bolivia and the University of Pennsylvania Museum

Wednesday, July 9, 2014

Two Current Bits of Nautical Archaeology

Mars was the largest ship in the world in its day. It exploded and sank during a battle in 1564.
Swedish warship Mars

A couple of quick marine achaeology links:

Recent news about the discovery of the remarkably intact 16th-century three-masted Swedish warship Mars. Not within our definition of "indigenous boats," but fascinating nonetheless (if you ignore the ludicrous "cursed warship" in the headline of the National Geographic article). 

Reader and contributor Edwin Deady sent me this link for a free online course in marine archaeology, offered by the University of Southampton. It starts in October and, according to the description, it does address non-European examples and topics.

Wednesday, June 25, 2014

Irish Logboat Finds

An article in the current issue of Current Archaeology tells of multiple logboat finds in Lough Corrib, County Galway, Ireland. I haven't seen the full writeup (it's pay-to-read), but a decent summary appears here.

The five boats, found in various locations around the large lake, were discovered during a bathymetric survey, and they were preserved by the lake's soft mud bottom and (presumably) cold temperatures and still waters at depth. One of the logboats, dated to about 4,500 BCE (Early Bronze Age), exhibits 2-3cm raised features carved on the inner side of the hull. There is a lengthwise feature that serves as a kind of keelson, and four cross-members. The article speculates that these served to divide the hull into compartments, but I think it more likely that they served as strengthening members in the nature of ribs.
Bronze Age Irish logboat (Source Current Archaeology)
The Early Bronze Age logboat found in Lough Corrib is 12 meters long and probably had a crew of 10-12 paddlers. (Source: Current Archaeology)
A 3,400-year-old boat was apparently carved in two halves, held together by rods that passed through internal cleats on the interior of both halves, and probably supplemented by lashings through bored holes. (The article summary is ambiguous on this point.) This strongly suggests kinship with the sewn-construction techniques used in England, as displayed in the Bronze Age Ferriby boats and Dover boat.

Another Lough Corrib boat, dated to the 11th century CE, was found in conjunction with several battle axes. Although battle axes were introduced to Ireland by Vikings a couple centuries earlier, the article states that it is more likely that the boat carried Irish warriors who had adopted the Viking weapon. Clear evidence for the use of oared propulsion exists in the form of holes for four pairs of tholepins. Five thwart-seats were present, indicating that the boat carried a coxswain or some other non-rowing individual (e.g., a passenger, dignitary or the captain). Clinker-planked construction was common by the 11th century, and of course skin-on-frame curraghs were also in use in Ireland at that time, so it is interesting that logboats remained in use for apparently high-prestige purposes that late in Ireland's history.