During the first decade of the nineteenth century, it was (almost) universally acknowledged that Humphry Davy's lectures at the Royal Institution on chemistry, electro-chemistry and geology, among other subjects, were by far the most attractive scientific spectacle in London. Much has been written about the popularity, the fashionability, the attractiveness and the patriotism (in time of war) of Davy's lectures. When Davy, aged 22, arrived in London in March 1801 he had never previously delivered a lecture, but within two months he had made his mark in the Royal Institution's new large lecture theatre, so much so that he immediately repeated his first course. How did his experimental demonstrations, full of spectacular sensory experience (noise, smell, light, touch) convey his scientific rhetoric? What resources, material and human, did he draw on? In this paper I will seek to understand how Davy constructed his practice as a lecturer and how it related to his chemical researches. As well as using Davy's lecture notes (now available through the Davy Notebooks Project), I will draw on the notes taken by some of his auditors, their comments in diaries and letters as well as administrative records and contemporary newspaper accounts.