the 1940s, shale was being carted from the Barigan deposits to the rail head at Lue – 25 km south east of Mudgee – on the second occasion, when additional oil was needed during the Second World War.) By 1911, Wall was operating gypsum (Calcium sulphate), dolomite (Calcium-Magnesium carbonate) and limestone (Calcium carbonate) quarries on Dolomite Road at Mount Knowles near Mudgee (possibly with his brothers Ignatius and Damian) and ran a private tramway to move the quarried stone to connect with the main railway from Mudgee to the Blue Mountains at Wall's Siding, Mount Knowles. Others were also quarrying in that area. "Messrs. G. & C. Hoskins being supplied by Messrs. Curlewis, also of Wall's Siding, the dolomite in this instance being calcined in a cupola furnace before railing to Lithgow". Wall's limestone and gypsum was also shipped to Sydney. In May 1911 he held Lease PL No. 232 adjoining the Traelman Gold mining Company at Ivy Paddock near Mudgee and was also investigating the setting-up of a 'hill-side' furnace on the Dunedoo rail line, near Mudgee. In October 1912, a William Wall is listed as holding a 4 acre mining lease at Yambulla (south of Cooma, NSW). In 1913, he was operating his business from offices adjacent to the London Hotel in Ardlethan, NSW. These rented offices were burnt down along with a few shops and the Bank of NSW on Christmas morning 1914 It must have been a significant set back at 69 to have lost all his professional equipment in this fire. He seems to have been well regarded there and played a significant role the mining affairs of the town. In 1915 he was operating mining leases around Ardlethan and Narian. The 1917 Sands Country Alphabetical Directory lists W. C. Wall as a Mining Agent at Ardlethan, NSW (80 km east of Griffith). Two years later in 1919 Wall was at North Yalgogrin, NSW (35 Km west of West Wyalong where gold was first discovered in 1893 on Robert Payne's selection 2 Km east of the township) mining gold and processing his ore at the Yalgogrin stamper battery. He was then 74. In the letter from Yalgogrin to his daughter Ethel (June 1919), he describes the severe drought at that time and states his intention to come down to Sydney via Mudgee as soon as he can process his ore at the Yalgogrin stamper battery.