LIST OF ILLUSTRATIONS 



FIG. 



1, 2. Methods of Laying out Triangulation Points. 



3. Scott & Godsir Rockcutter. 



4. Lobnitz Rockcutter. 



5. Saunder's Machine for Subaqueous Rock Excavation. 



6. Drilling Platform Used on the Danube River. 



7. Ingersoll Drilling Scow. 



8. Rand Drilling Boat. 



9. Boat with Submerged Caisson for the Excavation of Rock under the Rhine 



River. 



10. Plan of Flood at Hell Gate, N. Y. 



11. Honeycombing of Flood Rock showing the Direction of Drill Holes in 



Galleries. 



12. Plan of the Ledge of Rock at Henderson's Point. 



13. Method of Excavation Followed at Henderson's Point. 



14. Stone Lifter on St. Lawrence River. 



15. 16. Side View and Part of the Deck Plan of the Dredge " Ville de Rochefort." 



17. Dredge " Pas-de-Calais." 



18. Dredge "Cadiz." 



19. Dredge for the Marne Canal. 



20. Dredge for the Rhone River Propelled by Sprocket Wheel. 



21. Stationary Ladder Dredge. 



22. Stationary Ladder Dredge on the Fox River, Wis. 



23. Dredging Plant Used on the Fox River, Wis. 



24. High Tower Ladder Dredge "City of Paris." 



25. Allen Scraper Used on the U. S. Dredge "Manhattan." 



26. Rotary Cutter at the End of Suction Pipe. 



27. 28. Cross-section and Side View of the Centrifugal Pump of a Hydraulic 



Dredge. 



29. Hoppers in the Hydraulic Dredge "Nereus." 



30. Sand Pump on Dredge "Nereus." 



31. Dredge "Thomas." 



32. Cross-section of the Dredge "Thomas," showing Central Pit and Lateral 



Hoppers. 



33. Central Portion of the Dredge "City of Rouen," showing the Single Hopper 



Amidships. 



34. Dredge "J. Israel Tarte." 



35. Plan and Longitudinal Section of the Dredge " J. Israel Tarte." 



36. Floating Discharge of the Dredge " J. Israel Tarte." 



