It is alleged that Highs knew the jenny's limitations. It could produce only thread that was suitable for weft. Its output was too soft to be used for warp, which still had to be manufactured from linen. While Hargreaves worked on the spinning jenny, Highs, it is alleged, constructed a machine using rollers, similar to a machine later called the water frame. Whereas the jenny had stretched the thread by trapping it in a clove, a sort of wooden vice and pulling it out, the water frame achieved better results by passing the roving through two sets of gripping rollers. The second set were rotating at five times the speed of the first, so the thread was stretched to exactly five times its original length, before being given its vital twist by a bobbin and flyer. The machine produced stronger thread than the jenny. This thread that was suitable for warp. It is alleged that Highs gave clockmaker Kay a wooden model of his rollers and asked him to make a working metal version. Kay did so before returning to live a few miles away in his native Warrington.