Manningham Mill is bounded by several roads, Heaton Road is ancient but Beamsley Road and Patent Street, were probably created in their final form around 1870-75 when the mill itself was constructed. The name Patent Street alone would indicate that the roadway in question is not ‘historic’ in origin and its name was not recorded in White’s 1866 Directory. On the other hand the road is drawn on the Dixon & Hindle map of the Borough of Bradford in 1871 and is being used by 1874. In 1875 Bradford Council ordered that Patent Street and neighbouring roads should be ‘paved and sewered etc’ (Bradford Observer 11 Aug 1875). The question is whether the remarkable road surface could ever have been the work of the Borough Council. Beamsley Road was metalled with beautiful granite setts which don’t seem ever to have been covered in tarmac. Sandstone setts are more commonly used in Bradford but I assume that granite was chosen here because the road was the main access point to the rear of the mill and would have taken very heavy traffic. Patent Street has been covered in tarmac but below is a photograph showing the original surface emerging after weather and frost damage. Large numbers of rectangular blocks are visible, which are white or bluish in appearance. I assumed initially that these were Tees Scoria Company blocks which were made from iron smelting slag and are quite common further north; I have seen them in Whitby and York for example. However I obtained a sample of the Patent Street blocks and there is not much doubt that they are pieces of cut limestone. It was easy to prepare a polished section of the fairly thin block. The bottom surface looks like limestone and reacts with weak acid. The top surface appears white, polished and almost vitrified; it doesn’t ‘fizz’ when acid is applied; was this altered chemically when heating, or some other surface process, was applied at the top surface. I haven’t been able to trace limestone blocks or setts as a nineteenth century road surface, treated or not, nor can I say why they were chosen. They are clearly not as strong as granite and probably not more serviceable than the sandstone setts which local quarries could have produced. Was it a joke? Patent blocks in Patent Street. The uniform nature and the vitrified surface of the second image suggest some intervention….but what? The process evidently didn’t catch on as, so far, I have not come across anything similar elsewhere. A local history contact can remember the road surface before it was tarmaced, this being when she was a schoolgirl. The surface was very beautiful and the white, grey and blue blocks glittered like a fish’s scales. That would have been a sight worth seeing.