Herbert McLeod FRS (1841-1923) was Professor of Experimental Science (practical physics and chemistry) at the Royal Indian Engineering College situated just outside London at Cooper's Hill. This paper is an attempt to recreate something of his scientific and social world during his first fifteen years as a professor. It draws on a number of sources but is heavily based on McLeod's diary which contains daily entries from 1860 to 1923. Many events, places, scientific fashions and practices are mentioned, and for the fifteen years under consideration in this paper, the diary has a large cast of characters, including about three hundred people engaged in scientific or technical work. It recounts how McLeod and his peers moved through a range of scientific spaces such as laboratories and learned societies, through intellectual and technical sites such as spectroscopy, telephones and electrical lighting, through religious sites such as churches and mission meetings, and through a range of conventional social sites such as clubs, visits to each other's homes, and holiday locations. The sites can thus be defined in geographical, intellectual, disciplinary, institutional, material cultural or social terms. Movement through them led to the formation of many different personal, ideological and material associations and, as will be discussed, gave people access to a wide range of scientific and technical activity.