The mine was then filled in during the aftermath of the failed rising, but its existence was revealed to the government by an employee of the Erskines. Samples of the ore were analysed by Sir Isaac Newton and found to be very rich. Sir John was later able to secure a pardon for his role in the rising, on condition he revealed all he knew about the mine, and gave a tenth of the proceeds to the government. Mining resumed a few years later and the remainder of the deposit was extracted. Later, in 1759, a vein carrying erythrite, an ore of cobalt, was found and gave a new lease of life to the mines, but it was soon exhausted. Many of the old mineworkings can still be seen, but the new landowners, The Woodland Trust, have installed locked gates on the more extensive workings, as there are unprotected shafts within. There is not much trace of silver to be found now, as the dumps have been well worked over by mineral collectors. Some fine examples of crystallized dendritic silver were found in the 1980s. There are other mine workings at Carnaughton Glen, on the west side of Alva (just above the golf course), which are often confused with the Silver Glen. These are barren trials from the 1770s. Again, there is at least one shaft, this time water-filled, so casual exploration by the inexperienced is not advised. Woodstock, Cape Town  Woodstock is a suburb of Cape Town, South Africa, between the docks of Table Bay and the lower slopes of Devil's Peak, about east of the city centre of Cape Town. Woodstock is served by Woodstock and Esplanade railway stations, and has the postal code 7925 for street addresses and 7915 for post office box deliveries. The area was inhabited by Khoikhoi until the arrival of Dutch in the 1600s, Their subsequent decline followed as a result of fighting over land with the Dutch, imported European diseases and eventual assimilation into the Cape community. Three freehold farms (Zonnebloem, Leliebloem and Roodebloem) were established on the slopes of Devils Peak in 1692 and as the area became populated it became known as Papendorp - after Pieter van Papendorp, who had settled in the area during the mid-eighteenth century. By the middle of the 19th century, especially after the arrival of the railway line, Woodstock had become a fashionable seaside suburb with cottages next to the sea and a beach which stretched until the Castle of Good Hope.