ANCIENT AND MODERN WORKS. 9 



by Mr. George C. Morgan, C.E. This stand-pipe is a steel 

 cylinder, 4 ft. in diameter by 210 ft. in height, capacity 

 20,000 gallons. It is enclosed in an outer ring of stone and 

 brick masonry, with a 2S-in. annular space. The lower 50 ft. 

 is composed of in. steel plate; the upper rings not stated. 

 The pipe rests upon 18 ft. depth of solid masonry, and the 

 entire construction is supported by timbers arranged to form 

 a platform 24 ft. square, resting upon a sub-foundation of 

 water-bearing sand and gravel. 



Of the stand-pipes recorded, 228 are constructed of steel, 

 and 195 of iron, the remaining number uncertain. 



Besides the usual form of stand-pipes and tanks, there are 

 many towers and tanks, combination affairs, designed to 

 meet certain conditions where it may seem preferable to carry 

 the effective head of water by open structural supports, 

 rather than by utilizing the lower plate-rings of the shell to 

 enclose the sustaining water-column. These supporting 

 towers are of manifold design and construction, being built 

 sometimes of wood, but more frequently of stone or brick 

 masonry, latterly largely of metal. 



Tendency of Modern Practice. In this connection, the 

 " Manual" editorially says: 



<4 In the design of elevated tanks, curved bottoms have 

 recently been used in a number of instances, and steel sup- 

 porting towers or trestles are now commonly employed. The 

 elevated tank is now preferred by many engineers to the 

 stand-pipe, it being recognized that in many instances the 

 effective upper 20 or 30 ft. of water can be supported more 

 cheaply, and perhaps safely, by a trestle than by a body of 

 water enclosed in a cylinder. Where high hills are available 

 for sites, and storage is quite as important as pressure, stand- 

 pipes have advantages of their own." 



From compilations by the writer, the number of towers 

 and tanks at this time in the United States, utilized by city 



