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. Tms book results from the author''s experience in teaching the subject of Least Squares and the Adjustment of Observations to classes of civil engineering students at Cornell University. As the time allotted to this work became more and more limited, the available textbooks became less adaptable to the mom of the course. To meet this condition, a series of chapters entitled Notes on the Adjustment of Observations was prepared and used as a text. With these notes as a basis, this book has been written.