Smithsonian Report, 1913. — Wall<er and Bond. 



Plate 5. 



Diamond Drill Boring Horizontal Hole 1,100 Feet Below Hudson River. 



Constructing a Steel and Concrete Section of Aqueduct. 



This section consists of a steel pipe, lined internally with 2 inches of cement mortar, and em- 

 bedded in reinforced concrete. 



