b NEW YORK STATE MUSEUM 



the Catskill Aqueduct problem. His exceptional insight into . its 

 nature led to the adoption of measures in this direction that are 

 now proved to have been fully justified. A staff of geologists has 

 been maintained. From time to time engineers of the regular staff 

 who have shown unusual aptitude in such investigations have been 

 assigned to special duty on geologic exploratory work. In the pre- 

 liminary investigations of the Northern Aqueduct, Division Engineer 

 James F. Sanborn was very intimately connected with the geologic 

 work. With him the writer worked out many field studies that 

 later formed the basis of advisory reports, covering locations, kinds 

 of explorations to be made, and interpretations of data. No one 

 has had a better grasp of both the geologic and the engineering 

 aspects than Mr Sanborn. It is with great pleasure that the v/riter 

 acknowledges many valuable suggestions and much help through 

 association with him. In the later exploratory work within the city 

 similar service has been rendered by Mr John R. Healey, who has 

 much to do with the geologic detail of the delivery conduit data. 

 The consulting geologists employed by the board were Professors 

 James F. Kemp, W. O. Crosby and the writer. 



A special debt is acknowledged to Prof. James F. Kemp, consult- 

 ing geologist of the board, whose confidence in the writer's work 

 originally brought him into touch with these investigations as an 

 assistant, and with whom since that time many joint reports to the 

 board have been written. 



Valuable advice and assistance in arranging for the issue of this 

 report has been given by Department Engineer Alfred D. Flinn of 

 Headquarters Department. For some of the corrections and sug- 

 gestions special acknowledgment is made to Department Engineer 

 Thaddeus Merrimar , 



The department engineers, Robert Ridgway of the Northern 

 Aqueduct, Carlton E. Davis of the Reservoir, Merritt H. Smith, for- 

 merly of the Southern Aqueduct, Frank E. Winsor of the Southern 

 Aqueduct, William W. Brush and Walter E. Spear of the City De- 

 livery have given every facility for gathering geologic data within 

 their territory and have contributed largely to the better understand- 

 ing of their special fields. 



The geologic matter relating to special problems has been worked 

 out with the aid of the division engineers in direct charge in the 

 field. Among these must be mentioned L. White of the Esopus 

 division, William E. Swift of the Hudson river division, A. A. 

 Sproul of the Peekskill division, Lawrence C. Brink of the Wall- 



