Fire Investigation is a practical guide on the basics of fire investigation, with emphasis on ascertaining the cause of fire. Three items that constitute an acceptable cause of fire are highlighted: the source of ignition; the material first ignited; and the defect, act or omission which led to the source of ignition and the material first ignited creating a fire. This book is comprised of 11 chapters and begins with a discussion on sources of ignition and materials first ignited, paying particular attention to three temperature thresholds of combustible substances: flash-point temperature, fire-point temperature, and self-ignition temperature. Examples of sources of ignition are given, including ashes, soot, gas, and naked or open flame. Subsequent chapters deal with the reasons, motives, and methods of arson, as well as timing devices that may be used by arsonists; fire and non-fire explosions; variables that must be taken into account when trying to determine the rate of growth of a fire; and fatality occurring in a fire. The use of photographs and drawings in fire investigation is also considered, along with collection of samples and physical evidence from a fire scene and gathering of information through interviews. The final chapter presents abridged case histories of the six categories of arson. This monograph is written for students, fire officers and investigators, police officers, insurance investigators, and loss adjusters.