M1 motorway. It is crossed by a railway bridge, carrying the Sheffield and Rotherham Railway and the Sheffield Supertram, and finally joins the left bank of the River Don, opposite the Meadowhall Shopping Centre. History Between Blackburn village and Grange Lane the brook originally formed the boundary between Sheffield and Rotherham. It is joined by Hartley Brook Dike, near the junction of Ecclesfield Road and Sicey Avenue. With the coming of the South Yorkshire Railway in the 1850s the course of the brook was straightened to run parallel with the trackbed through the valley; however the boundary continued to follow the original course. It runs in a culvert along part of the course by the railway line, which is now closed and forms part of the route of the north–south section of the Trans Pennine Trail alongside the brook. Water power The brook provided power for a number of mills along its course, including the New Mill and the Old Mill at Ecclesfield. Joseph Hunter in his book Hallamshire wrote in 1819 that all the nails manufactured in Hallamshire were made in Ecclesfield, and further downstream the river provided power for the manufacture of forks. There were at least four sites on Whitley Brook that used water power, and another four on Blackburn Brook below its junction with Whitley Brook. The furthest upstream was at Whitley Mill, which was in the grounds of Whitley Hall. The mill was mentioned in 1587, when it was part of the estate surrendered to George, Earl of Shrewsbury by its owner William Parker. By 1617, it was back in the hands of the Parker family, for Francis Parker surrendered both the mill and a kiln, used for drying the corn. There are no clear records of the demise of the mill. The use of water for milling was contentious as far back as 1440, when there was a complaint that "the water at Whitleyfeld had been turned back from its right course to the detriment of the Prior of Coventry." Whitley Brook is joined by another stream, which passes through an area called The Wheel. Clear evidence of a mill dam and the remains of a well-preserved tail race were present in 1949, although no name for the site has been found. Rev J R Eastwood thought it might have been a grinding wheel owned by Alexander Schyrtclyff and mentioned in 1520. Besides being