The classification or division of the matter of the text, and the table of contents, have been made so complete, with a view to convenience even of the desultory reader in seeking any particular subject or paragraph, that no index has been prepared, as it is believed that the table of contents, as arranged, practically supplies the information ordinarily given by a comprehensive index. Complete and detailed treatments of the purely technical matters covered by Part II will be found in the author’s “Elasticity and Resistance of Materials” and in his “Stresses in Bridge and Roof Trusses, Arched Ribs and Suspension Bridges.” W. H. B. COLUMBIA UNIVERSITY, October 24, 1902. CONTENTS. PART I. _ANCIENT CIVIL-ENGINEERING WORKS._ CHAPTER I. ART. PAGE 1. Introductory 1 2. Hydraulic Works of Chaldea and Egypt 2 3. Structural Works in Chaldea and Egypt 4 4. Ancient Maritime Commerce 7 5. The Change of the Nile Channel at Memphis 8 6. The Pyramids 8 7. Obelisks, Labyrinths, and Temples 12 8. Nile Irrigation 13 9. Prehistoric Bridge-building 14 10. Ancient Brick-making 15 11. Ancient Arches 16 CHAPTER II. 12. The Beginnings of Engineering Works of Record 19 13. The Appian Way and other Roman Roads 20 14. Natural Advantages of Rome in Structural Stones 22 15. Pozzuolana Hydraulic Cement 24 16. Roman Bricks and Masonry 25 17. Roman Building Laws 27 18. Old Roman Walls 27 19. The Servian Wall 28 20. Old Roman Sewers 29 21. Early Roman Bridges 31 22. Bridge of Alcantara 35 23. Military Bridges of the Romans 35 24. The Roman Arch 36