Photos courtesy of Greg Daughtry of rec.climbing. Reproduced here is part of the instructions he wrote for the post to rec.climbing. Well, I haven't seen this published in the books or mags, and I was thinking about submitting it myself, but here's my contribution to help improve the signal to noise ratio. Since I didn't come up with it, I guess it belongs in the public domain... It seems that adjustable daisy chains are all the rage these days for aiding, and general clipping-in to anchors. Well, if you don't want to spend the $25 bones for a store-bought one, and you tend to carry cord for prusik slings anyway, you can use Purcells as a nice $3 alternative... Read on.. The Purcell is an alternate tying of a prusik sling that can be used as an adjustable tie-in, here's how to do it: You need ~15 feet of 5-6mm perlon. A convenient length is 3x the length from the ground to your chin, as this yields a functional length purcell. You can have a second one slightly longer (3x lenth to your head). You can easily tweak the lengths to dial in your mojo.