In developing countries, like Kenya, crushing stones into aggregates for the construction industry using a manual "hammer-anvil" is common. This activity is carried out by men, women, and children along roadsides, riverbeds, homesteads, and near towns. Manual stone breakers do heavy work and expose themselves to health problems like body, eye, ear, and skin injuries. Moreover, the aggregate produced is of low quality and the business is hardly profitable. Therefore this book concerns itself with establishing the design parameters for the development of a Jaw Stone Crusher for Small Scale Entrepreneurs. The equations derived can be used to investigate the effects of alterations in the design of the jaw stone crusher mechanisms upon its kinematics and mechanical advantage. The Vector Closure Method together with the well-known Freudenstein's equations has been applied. This book is also handy for university undergraduate students studying the mechanism of machines.