Thank you all for the very nice comments.
Spent most of the day with my wife in the local hospital, but did manage to start on the bow string. Started with a 10" circle of whitetail rawhide. This was just like the other cordage I showed before. I did scrbe each circle cut at 3/8" all the way around and repeated this until I had about 12 feet of 3/8" strap and a roughly 3" circle left in the center. Next I tied the rawhide to a nail at the mid-point of the strap.
Next you want to place the two straps one on top of the other and give a few twists....continue down the strap to the other end making sure you maintain both straps flat and even to each other. When ya get to the end tie a knot (double over-hand and work the knot tight) I use this knot to hold a spring clamp at the end without sliding off.
Since the rawhide is slippery this clamp helps this old one hander to keep tension on the line and continue to twist.....the most important reason is that the clamp can be fastened down (so the cord cant "unwind") and I can keep the tension AND still use the good hand to work the string. By work the string I mean use your hand to grab the sting and squeeze the string as you work it back and forth. This helps even out the wraps, the diameter, and trains the cord to be what ya expect out of it. You repeat this "pull,twist and rub" until you are at the diameter you want, the twists as even as possible, and good tension on the string. The string wrings water out as you twist it and the rubbing down spreads this liquid out evenly. If you think about it this liquid is actually "hide glue".
When you think you are where ya want to be ya got one more job. With the string all twisted and good tension on it, get your hands wet and shake 'em off then put the string between your palms press pretty hard together and roll the string back and forth ...repeat this progressively down the entire string. The reason for slightly wet hands is by now the string will actually be getting "sticky". Now just keep your eye on it for a few hours and it needs to get rolled again etc. ya can continue to do it. Once the string is barely damp it wont change much any more.
Two sets of pics, hope I took enough maybe not, please if any questions make sure to ask.
rich