For over thirty years - from 1872 to the early 20th century - the main public transport in São Paulo was the tram pulled by mules. Today, every association for animal's protection would deter such use, but it actually did exist. This book retrieves the history of trams in São Paulo. The project came up during a research carried out at the Fundação do Patrimônio Histórico da Energia de São Paulo, responsible for keeping the collection of former Light - The São Paulo Tramway, Light and Company -, which during decades was in charge of the public transport in the city. Most photographs in this book belong to that collection. A number of them belong to the newspaper O Estado de São Paulo, including those from the São Paulo de Piratininga Collection.