The freedom with which the author has drawn from English and American sources as well as from Continental practice gives the work a value not found in other treatises upon machine de sign, while the vast improvement which has been made by the introduction of the kinematic analysis and_the resulting classification of the details of the subject, cannot fail to appeal to the instructor as well as to the practising engineer. The translation has been made from the Fourth Enlarged German Edition of 1889, the last which has appeared in the original, and is complete and unabridged in every respect. The introduction to this edition is especially worthy of note, as it contains the author's summary of the principles set forth in his larger work on Theoretical Kinematics, and the more so as it includes a brief glance at the still wider subject included in his work on Applied Kinematics, as yet unpublished in Germany, and embodying a mass of manuscript which it is trusted will at no: distant day be given to the public.