During examination and joining, textile fibers are found on both the knobs and rotating sleeves of the instrument. The fibers have a clean, undyed appearance and are beautifully preserved. Some of the fibers seem to repeatedly wrap around the rotating sleeve or knob, while others wrap through holes at the top of the knob. Below, yarn looks to be going through the hole of the knob to form a loop.
The exact use of the fibers is unknown, but it is postulated that the yarns might seal areas around the rotating sleeves to prevent air leakage, assist in the rotation of the sleeves in some way (perhaps by giving the player a way to turn the sleeves through pulling the yarns), or cushion the sharp top edge of the knob with wrapped fibers to make playing more comfortable. It’s possible they were simply used as decoration.
When the fibers below are studied by textile conservators, it becomes apparent that the fibers, extremely well preserved and very fine, form two-ply yarns twisted in an “s” direction.
The fibers are further examined using polarized light and are identified as fine flax fibers. In the image below, the fiber has two very strong nodes and several areas of cross hatching. These elements are common to bast plants, such as flax, which pull water from the earth like straws as they grow, with nodes forming at the points of growth. The image was taken using polarized light, a 40X objective, and a red tint plate to accentuate the visibility of the nodes present across the fiber.
The fibers are highly crystalline and almost glassy in appearance, with sharp break edges and a high degree of birefringence, probably due to mineralization that occurred during burial. Their diameters are also very small, ranging from 5-15 micrometers, with an average diameter of 11.4 micrometers. The average for modern flax fibers typically ranges from 11-16 micrometers, but early flax has been recorded in the archeological record with much smaller diameters.
Early flax fibers of this type are common in the highly prized and finely processed flax of ancient Egypt. Termed “ultra fine fibers” by archeologists and textile historians, these fibers are most likely obtained from young flax plants and processed in a manner that differs from modern flax processing. It is postulated that young flax plants were used after retting without hackling, and that they were spliced together in the hand of the spinner and twisted into yarns using a drop spindle. In the archeological record, these fibers are routinely made into two-ply "s"-spun yarns, as seen on the auloi. In no other bast plant is it possible to have such fine fiber diameters in a processed yarn.
For flax processed in this way, it is also customary to find areas on the fiber bundle where the growth nodes of the plant are still aligned as they would have been in the stalk of the plant during growth. To see if this is also true of the flax from the auloi, samples of the fiber are examined using the scanning electron microscope (SEM). Below, the arrows point to areas where the nodes line up from fiber to fiber; these areas look like dislocations along the length of the fiber.
In the SEM, no distinct splices are found joining fiber to fiber, but it is possible in some of the SEM images to see the growth nodes aligned, giving credence to the idea that the flax used on the auloi during the Meriotic period is similar to the extremely fine flax produced throughout the ancient world and likely to have been processed in a similar manner.
Fibers are also found wrapped around the joining section of a bone core from a mouthpiece. This is a significant find because fibers have not been seen in this context on auloi before. In the images below showing the location of the fiber on the bone core and a detail of the fiber wrapped over the bone, the green tint comes from the copper-containing metal of the pipe reacting with organic material during burial.
The state of preservation of these fibers is exquisite. Like the fibers found on the body of the instrument, they are very fine, clean, crystalline flax fibers with small fiber diameters.
Unlike other examples, these fibers appear to have been used without twisting, and were probably wrapped to cushion the join, sealing it to prevent air leakage during playing. However, like the previous fibers, they also show an unusually low degree of processing. In the image above taken with crossed polars with a 40X objective, it is possible to see the nodes aligned across fibers.