Mr (sometimes Brother or Father) Edmundus Gisler was a member of the Society of Jesus (Jesuits) who was associated with the Catholic church at Dunbrody, a settlement on the Sondags River some 35 km north-north-east of Uitenhage in the Eastern Cape. From 1893 he made regular meteorological observations for the Cape of Good Hope Meteorological Committee, which published the results in its annual reports. He was also responsible for one of the few evaporation stations that reported to the committee during the 1890s. From 1897 his meteorological station was one of those classified by the committee as a second order station. He sent in his observations, including evaporation values, continuously until 1903. The next year these duties were taken over by Rev. A. Vogt.
[Up to about 1970 the highest air temperature ever reliably recorded in South Africa was 49.9 degrees Celsius, recorded at Dunbrody during berg wind conditions in January 1925].