Collapse_ How Societies Choose to Fail or Succeed - Jared Diamond [60]
The still-visible transport roads on which statues were moved from quarries follow contour lines to avoid the extra work of carrying statues up and down hills, and are up to nine miles long for the west-coast ahu farthest from Rano Raraku. While the task may strike us as daunting, we know that many other prehistoric peoples transported very heavy stones at Stonehenge, Egypt’s pyramids, Teotihuacán, and centers of the Incas and Olmecs, and something can be deduced of the methods in each case. Modern scholars have experimentally tested their various theories of statue transport on Easter by actually moving statues, beginning with Thor Heyerdahl, whose theory was probably wrong because he damaged the tested statue in the process. Subsequent experimenters have variously tried hauling statues either standing or prone, with or without a wooden sled, and on or not on a prepared track of lubricated or unlubricated rollers or else with fixed crossbars. The method most convincing to me is Jo Anne Van Tilburg’s suggestion that Easter Islanders modified the so-called canoe ladders that were widespread on Pacific islands for transporting heavy wooden logs, which had to be cut in the forest and shaped there into dugout canoes and then transported to the coast. The “ladders” consist of a pair of parallel wooden rails joined by fixed wooden crosspieces (not movable rollers) over which the log is dragged. In the New Guinea region I have seen such ladders more than a mile long, extending from the coast hundreds of feet uphill to a forest clearing at which a huge tree was being felled and then hollowed out to make a canoe hull. We know that some of the biggest canoes that the Hawaiians moved over canoe ladders weighed more than an average-size Easter Island moai, so the proposed method is plausible.
Jo Anne enlisted modern Easter Islanders to put her theory to a test by building such a canoe ladder, mounting a statue prone on a wooden sled, attaching ropes to the sled, and hauling it over the ladder. She found that 50 to 70 people, working five hours per day and dragging the sled five yards at each pull, could transport an average-sized 12-ton statue nine miles in a week. The key, Jo Anne and the islanders discovered, was for all of those people to synchronize their pulling effort, just as canoe paddlers synchronize their paddling strokes. By extrapolation, transport of even big statues like Paro could have been accomplished by a team of 500 adults, which would have been just within the manpower capabilities of an Easter Island clan of one or two thousand people.
Easter Islanders told Thor Heyerdahl how their ancestors had erected statues on ahu. They were indignant that archaeologists had never deigned to ask them, and they erected a statue for him without a crane to prove their point. Much more information has emerged in the course of subsequent experiments on transporting and erecting statues by William Mulloy, Jo Anne Van Tilburg, Claudio Cristino, and others. The islanders began by building a gently sloping ramp of stones from the plaza up to the top of the front of the platform, and pulling the prone statue with its base end forwards up the ramp. Once the base had reached the platform, they levered the statue’s head an inch or two upwards with logs, slipped stones under the head to support it in the new position, and continued to lever up the head and thereby to tilt the statue increasingly towards the vertical. That left the ahu’s owners with a long ramp of stones, which may then have been dismantled and recycled to create