Much of the world's surface, even under the oceans, is covered in thick deposits of sedimentary particles - gravel, sand, silt and clay. The nature of the deposits and their formation is very much dependent on the distribution of particles of different sizes. However, different instruments measure different attributes of a particle's size, based on how fast a particle settles in water, or the surface area of a particle, or its length. This book provides information on the how and why of particle size analysis in terms of understanding these sediment deposits.