In revising this work, it is recognized that the use of some of the ingredients are now prohibited by regulation in the United States, but in some instances, it has been seen fit to not change the original formulas. In some instances, however, the omission of the objectionable ingredient has been made, though otherwise the formula remains the same as in the first edition. Many formulas rendered obsolete are omitted on account of conflicting with pure food laws. The information furnished in these pages is based upon the author’s experience, there being very little theorizing upon the possibilities of what may be accomplished by adopting certain prescribed methods. For this reason, the book will be found of practical value to those interested in the meat packing business. The present necessity of a work on packing house operation is more evident than when the first edition was published. The original work has been entirely revised where considered necessary, amplified in places and much new information added. The chapters relative to construction, refrigeration and mechanical operation have been revised to conform to advanced practice. Acknowledgment is made of the use of engravings, photographs and original data, and ideas developed and used by the reviser in his engineering practice. That the volume will be well received and fill the needs as a hand book and reference work is the hope of the authors and publishers. The assimilation of the contents as a foundation, together with power of observation and application will greatly assist beginners in packing house work, the methods of which are progressing--although the fundamentals remain the same. The reviser hopes assistance will be given in this way, which he in turn received by oral advice from the two outstanding superintendents in their day (the days of the business growth), Messrs. F. W. Wilder and C. O. Young. D. I. DAVIS. Chicago, July 1, 1921. TABLE OF CONTENTS. CHAPTER I. MODERN PACKING HOUSES 1 Introduction and Growth -- Concentration -- Early Methods -- Yankee Ingenuity -- Chicago Yards -- Movement Westward -- Economic Factors -- Saving By-Products -- Pioneer’s Troubles -- Using Box Cars -- Using Refrigerator Cars -- Chilling Rooms -- Mechanical Refrigeration -- Freezing Meats -- Overseas Shipments. CHAPTER II. LOCATION AND CONSTRUCTION 9 Location -- Water Supply -- Sewage -- Odors and Prevailing Winds -- Cleanliness -- Designs and Errors -- Character of Business -- Requirements -- Principles of Design. CHAPTER III. PLANT DESIGN 14