Rudolf Streiff was born on 19 May 1873 in Vienna. After the death of his father, who was an engineer, his mother returned to her home town in Switzerland. Here in the house of his grandfather Rudolf passed a happy youth in very simple surroundings. While at school he had already shown considerable artistic talent. As his wish to become a naturalist appeared to his mother to promise an uncertain career, he went to the Technical College in Winterthur to become an engineer.

In 1894 Streiff left his home in order to emigrate to Brazil. With considerable endurance and untiring industry he was able, together with his younger brother, to build up a sound and promising business in a few years; this remained under his management for two decades.

After his return in 1919 with his family, he was able to fulfil the dream of his youth of becoming an investigator into the problems of nature. His principal interests were the föhn and the flow of glaciers. As a keen mountaineer he had many opportunities of carrying out observations and measurements on glaciers, which he was able to continue in later years. From 1922 onwards many publications on these subjects appeared in his name, as is well known to readers of the Journal of Glaciology. In a rough list I have compiled I find that at least thirty-two papers appeared under his name in the years 1922–1957.

In 1940 he was made an Honorary Member of the Naturforschende Gesellschaft of the Canton Glarus. He was also an Honorary Member of the Glacier Commission of the Schweizerische Naturforschende Gesellschaft; he was also one of the keenest members of the Zürcher Gletscher Kommision.

All who had the good fortune to come into contact with his delightful personality, and his enthusiasm for everything that was true and good, will always hold his memory in honour.