Machine derived contents note: Preface; 1. Introduction: The conceptual structure of nineteenth-century physics; 2. The context of physical theory: energy, force and matter; 3. Energy physics and mechanical explanation; 4. Matter and force: ether and field theories; 5. Matter theory: problems of molecular physics; 6. Epilogue: the decline of the mechanical world view; Bibliographic essay; Sources of Quotations; Index