26—the Application of Searle's Single and Double Pendulum Methods to Single Fibre Rigidity Measurements

Scaled-down versions of the classical Searle's apparatus are described in detail, and means of avoiding possible errors are indicated. The importance of measuring the linear density of individual specimens is discussed, and an instrument is described which facilitates the length measurement and mounting of the specimens under a standard tension. Rigidity and modulus data are tabulated for twenty-seven samples embracing a range of fibre types.