Distinguished as applied scientist and business administrator. Joining CSIRO as a research scientist, Zeidler later founded its Chemical Engineering Section. Recruited by ICIANZ in l952 to establish its Research Laboratory, he rose spectacularly to Chairman in l973 and piloted ICI Australia through a period of rapid expansion during which he backed research and development consistently and strongly. A director of several of Australia's most influential companies, following retirement from ICI in 1980 he became chairman of the committee to report to the Australian Government on the sharing of power resources in South-Eastern Australia. Indefatigable in community service, especially in education, he served on the CACAE, the Sweeney and the Williams Committees. He is Vice-President of The Walter and Eliza Hall Institute, the Defence Science Committee, and the Australian Academy of Technological Sciences.