 Complete the following phrase:  He now advocated the use of the narrow gauge of with all major construction in wood, which system he had developed since the early 1860s. Pihls ideas had been noticed in Britain where the smaller Ffestiniog Railway in Wales was also proving a success. After a visit to Norway the gauge was taken up by Sir Charles Fox and Sons, the firm founded by the eminent engineer and constructor of the Crystal Palace at the 