In an earlier book, Rheological Measurement (A. A. Collyer & D. W. Clegg, Elsevier Applied Science, 1988), the basic rheological methods of measurement presently used were discussed in the light of the basic underlying principles and current theories. The same approach is adopted in this companion book, which is concerned with some newer or more sophisticated techniques that have resulted from a fresh understanding of the subject, or as a result of improvement in computer control, data acquisition and computational power, or more simply from an industrial need, particularly with regard to process control. The first two chapters deal with the extensional flow properties of fluids and their measurement. This inclusion is in response to a greater awareness in industry of the importance of these flows. Chapter 3 intro­ duces and develops the subject of surface rheology and the measurement of its properties, again a subject of increasing significance. The methods of measurement of the dynamic mechanical properties of fluids and the calculation of the resulting rheological parameters are discussed in Chap­ ters 4-7 inclusive. The subject areas covered are: large-amplitude oscilla­ tory shear, a model for viscoelastic fluids and solids, a new method of measuring dynamic mechanical properties, particularly for curing sys­ tems, and the use of complex waveforms in dynamic mechanical analysis.