Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. HE use of the fan in general engineering practice is rapidly increasing, making it imperative that both the engineer and the architect become familiar with the fundamental principles governing the selection and application of fans for various purposes. Some general information has been published on the subject by the different fan builders, but what has' been given out has always been incomplete and frequently misleading, and did not afford sufficient data to be intelligently employed by the engineer. Heretofore no effort has been made to collect and present under one cover the latest and most reliable engineering data concerning fans and their application to various industrial requirements. This book is intended to be used as a guide in the selection and application of fans, heaters and kindred apparatus, and an effort has been made to so standardize the rules and data given that they may be used with any standard make of equipment. The greater part of the data presented is the result of tests and research made by the engineering staff of the Buffalo Forge Company in the testing laboratories of the company, many of the investigations being made purposely to obtain data for this book. The results of these investigations have in most cases never been heretofore published except in the proceedings of some of the engineering societies, where they were presented by the engineers of this company, and others. The rules and ap plications as outlined are the same as are used in this company's practice. In preparing this work the theory has been generally omitted, except in such elementary form as was necessary to an understanding of the facts given. The information herein presented is in complete and reliable form for standard applications, but there are many cases requiring special consideration from the engineer familiar with fan installations.

HE use of the fan in general engineering practice is rapidly increasing, making it imperative that both the engineer and the architect become familiar with the fundamental principles governing the selection and application of fans for various purposes. Some general information has been published on the subject by the different fan builders, but what has' been given out has always been incomplete and frequently misleading, and did not afford sufficient data to be intelligently employed by the engineer. Heretofore no effort has been made to collect and present under one cover the latest and most reliable engineering data concerning fans and their application to various industrial requirements. This book is intended to be used as a guide in the selection and application of fans, heaters and kindred apparatus, and an effort has been made to so standardize the rules and data given that they may be used with any standard make of equipment. The greater part of the data presented is the result of tests and research made by the engineering staff of the Buffalo Forge Company in the testing laboratories of the company, many of the investigations being made purposely to obtain data for this book. The results of these investigations have in most cases never been heretofore published except in the proceedings of some of the engineering societies, where they were presented by the engineers of this company, and others. The rules and ap plications as outlined are the same as are used in this company's practice. In preparing this work the theory has been generally omitted, except in such elementary form as was necessary to an understanding of the facts given. The information herein presented is in complete and reliable form for standard applications, but there are many cases requiring special consideration from the engineer familiar with fan installations.