No. 7 of 51 (PAJ2051 - PAJ2101): inscribed by the artist on the album page, as title, and signed in monogram initials and dated 'JHB 8/67', lower left on the drawing. The location shown by Butt is not specific but both the mountainous north-west corner of Taiwan, and the north side of the Tamsui River south-west of Keelung City (then Kelung Harbour), are areas of volcanic activity producing sulphur deposits which were mined there. Neither were difficult to reach at this period, either from the north coast at Kelung, or from Tam-sui Harbour on the north-west coast, and it is likely that Butt made his expedition from the former. In Butt's drawing the rock around the fumaroles is tinged sulphur yellow and two figures shown in the centre for scale are probably Westerners, although this is not entirely clear.