This text elucidates the entire science of hatha yoga (asana, pranayama, shatkarma, mudra and bandha) as it was conceived and practised not only for health and fitness but for awakening the vital energies: pranas, chakras and kundalini shakti.It points out that hatha yoga is not just a physical practice but a process of cellular transmutation from gross to subtle to divine. Thus hatha yoga was considered to be the foundation of all higher yogas. Line drawings and diagrams illustrate the text.