The combination of a good water power site (described by Rodgers as "by far the finest of any site within the lowland" the Manchester region) and a workforce used to textile factory work meant Stockport was well placed to take advantage of the phenomenal expansion in cotton processing in the late 18th century. Warren's mill in the market place was the first. Power came from an undershot water wheel in a deep pit, fed by a tunnel from the River Goyt. The positioning on high ground, unusual for a water-powered mill, contributed to an early demise, but the concept of moving water around in tunnels proved successful, and several tunnels were driven under the town from the Goyt to power mills. In 1796, James Harrisson drove a wide cut from the Tame which fed several mills in the Park, Portwood. Other water-powered mills were built on the Mersey.