20O TOWERS AND TANKS FOR WATER-WORK'S. 



Balcony. The necessity for a circumscribing balcony has 

 been discussed and emphasized. Its design permits considerable 

 latitude in the ornamentation of brackets, railing, and other 

 details. While wooden floors are frequently used as shown in 

 Fig. 51 and Fig. 56, a simpler and more durable floor is that 

 made of segmental steel plate, \ to 5/16 inch thick, with drain 

 holes as shown in details of Fig. 57. Small and cheap water- 

 towers generally have a gas-pipe post and balcony rails, but the 

 effect is poor and generally unsatisfactory. 



Supply Pipe. Flanged pipe is sometimes specified for the 

 supply main, but the ordinary cast-iron pipe of the bell and spigot 

 type answers every purpose. An expansion joint should be 

 insisted upon, located near the tank connection. Such a joint 

 is shown in Fig. i. In full hemispherical bottoms, the lower 

 plate is usually formed of dished steel head, and at its lowest 

 point a standard expansion joint should be riveted. 



Where the vertical inlet pipe enters the distributing system,. 

 a cast-iron foot elbow should be provided, with flat base plate 

 resting upon a masonry pedestal. The lower part of the pipe 

 and elbow should be incased in a circular masonry chamber as 

 a protection and support of a frost case where this is necessary. 

 Where the supply pipe is comparatively small, a water-gate 

 should be inserted at a convenient height above ground and 

 provided with a hand- wheel, otherwise the valve should be placed 

 on the distributing main just outside of the foot bend. 



Frost Proofing. In icy latitudes the supply pipe should be 

 protected from freezing by a frost-case. In extremely cold 

 climates the tank bottom is tapped for a steam-pipe, which is 

 led inside of the case, but ordinarily this detail is omitted, and 

 only wooden boxing or circular laggings, constructed with layers 

 of tar-paper between the sections of lagging, spaced to provide 

 from two to four 2-inch air spaces, is specified. A neater and 

 more durable construction is to make the outer casing of light 

 steel plate, say 3/16 inch, flanged with light angles and bolted 



