His interest in heredity led Galton to anthropometry; that is, the measurement of human characteristics. It had become clear to him that statistical investigation of data was reliable only when dealing with large sample sizes. In order to collect a sizeable amount of data he created an "Anthropometric Laboratory", which was included in the International Health Exhibition held in London in 1885. As part of this work, Galton devised the first scientific mental measurements, and thereby founded psychometrics.
The (First) Anthropometric laboratory at the International Health Exhibition
The laboratory tested exhibit goers with instruments that Galton often had to design himself and have made to his specifications. His mechanical ingenuity quickly produced many of instruments and techniques, most of which were highly successful.
Some of Galton's instruments for measuring
vision.
Subjects were happy to pay for the privilege of being tested, in exchange for a copy of their measurements. In this way Galton was able to collect over 9000 sets of data for different individuals, obtaining a reasonably representative sample. However, Galton's collection of data was so successful that processing it all was a problem; doing so required many hours of dedicated effort, and the required techniques for analyzing it had yet to be invented. Proper treatment of a sizeable portion of this data would have to wait until the 1920s and 30s.
Following the enormous success of his exhibit, Galton established a permanent version of the laboratory at the South Kensington museum, and continued to collect data for many years. The first full analysis of this data would only take place in 1980s, when the statistical techniques and computer-based analysis were mature and fast enough to handle the task.
Franz Boas, the famous anthropologist, was aware of Galton's work, which he refers to in the following article: 'Remarks on the theory of Anthropometry' published in the Journal of the American Statistical Association, in 1893.
Galton's other anthropological writings ranged from race to demography; they reflect his long running involvement with the Royal Anthropological Institute, and his determined efforts to ground the discipline in the gathering and analysis of hard data.