Before carefully excavating the blocks, the team took x-rays and CT-scan images of them to compile three-dimensional data about the bones, artifacts, and other material.
From this data, the researchers were able to develop a spatial image of where everything was in the submarine before its removal.
Concerns arose about handling the bones, textiles, and other fragile material that were among the artifacts. "Nobody knew how to handle the textile remains," Jacobsen said, adding that the team consulted experts around the world.
In the end, it was decided that the best approach was to remove the material in a controlled lab environment similar to the underwater conditions in which the objects lay for more than a century. The researchers created freshwater tanks outfitted with trays to hold the blocks of material.
Suspended in water, the buoyant textiles, for example, could be safely removed from the sediment by dissolving the mud with gentle streams of water from a syringe, and removing it with a small suction pipe.
The painstaking process enabled the team to separate the human remains and compile an inventory of them.
The excavation has turned up a variety of interesting artifacts besides the human remains. Last year, excavators uncovered a gold coin carried by the sub's captain, Lt. George Dixon. Stories had long held that the captain carried such a coin as a good-luck piece after it had saved him from death by a bullet. More recently, Dixon's ornate, gold pocket watch was recovered from a block of sediment. Conservators have not yet opened it to examine the interior and find out whether the contents include an inscription or photo.
"It is also possible that there is a pocket of ancient air trapped in a sealed interior compartment," Jacobsen speculated. "If that is the case, we will attempt to sample the air as well. A pristine sample of air from a secure 1864 date would provide important data to scientists studying atmospheric changes, she said.
From the skeletal remains, the researchers are working to determine each crew member's age, sex, height, and body build. Besides aiding identification, the analysis will provide important clues to injuries, infections, or other conditionssuch as wartime malnutritionthat may have affected the soldiers.
In addition, the osteological experts will analyze the skeletal data for this group and compare their individual data with similar data from other Civil War era remains. The purpose is to understand how this group fits statistically with rest of the North American data assembly.
Forensic expert Owsley has said the research might also yield information about the activities of the crew members while they were aboard the doomed vessel. He said he was able to determine from examining the bones, for example, that some of the crew members had been on the submarine longer than the others.
Because the skulls of the soldiers were so well preserved, scientists can do facial reconstructions showing what the crew members might have looked like. That work is expected to be completed about nine months from now.
As the investigations continue, specialists will conduct DNA analysis of the human remains. This data is of particular interest to project genealogist Linda Abrams, who is researching the personal histories and family lineages of each Hunley crew member. Eventually, the DNA materials may be able to link the crew members with their living descendants.
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