The paper reviews the development of resistors as unitary components for use in telecommunication equipment, leading up to the latest forms of “high-stability” film resistors. Sections 1 and 2 contain brief résumés of the historical development and of the construction and properties of eight different types, whose individual characteristics determine to a large extent the particular uses for which they are most suited. Section 3 is a review of the development of the “cracked-carbon” type, often referred to as “high-stability” resistors to differentiate them from the other carbon and composition forms which are liable to have a wider range of spasmodic variations of resistance due to ageing or to ambient conditions. Sections 3 and 4 deal further with the manufacture and the main electrical and high-frequency properties of such resistors.An extensive Bibliography enables additional data on various aspects of resistor construction, uses and properties to be obtained.