Plumbing 



217 



port at the bottom and perhaps in the upper interval, to keep it from vibrat- 

 ing and thus loosening the working parts. To protect this pump from freezing it 

 is advisable to drill an -inch hole in 

 the pipe, some 5 or 6 feet below the 

 supporting platform, so that the water 

 will readily drain off to a safe level after 

 use. This hole will cause but a slight 

 loss of water and will save much annoy- 

 ance and expense. 



There are two kinds of attic tanks, 

 the wooden, with metal lining, and the 

 all-metal tank. The former is made of 

 plank and usually put together with tie- 

 bolts (see Fig. 37). There are but two 

 linings for this worth considering, sheet 

 lead and sheet copper. Lead was the 

 first material used and lasts very well, 

 but has gradually given way to copper 

 and the all-metal tank. This is largely 

 due to the poisonous qualities of the 

 former under certain conditions. Lead 

 well covered with water collects (as 

 we have elsewhere stated) a fine sedi- 

 ment which protects it from corrosion 

 by the action of the water, the real source of danger. If the water be drawn 

 from the tank or in any other way the wet lead is exposed to the action of the ai~, 

 then corrosion begins. In this alternate wetting and drying lies the danger; such 

 conditions are likely to occur in one way or another; it is safer not to use lead. 



Sheet copper should be Hned with tin, as bare copper is even more poisonous 

 than lead under such conditions. In large copper-lined 

 tanks, owing to the limited sizes of the metal sheets, joints ' 

 must of necessity be made. These joints may be of the sort 

 termed double or lock seams, in which the two sheets of 

 metal are turned into one another, hammered flat and then 

 carefully soldered together. 



Wooden tanks are sometimes made without lining, 

 more particularly when of large size. In such cases, as in 

 fact with all tanks, the tank should be slightly elevated and 

 rest on a metal tray some 2 or 3 inches deep and pro- 

 jecting perhaps a foot beyond the tank on all sides. Th's, 

 connected with a fair-sized drain, should protect the house 

 in case of leakage. 



The cast-iron sectional tank, as its name indicates, is 

 made of separate adjustable parts or plates which are 

 bolted together, using cement joints. The separate sections are easily handled 

 and adjusted, owing to their comparatively small size. Its lasting qualities are good. 



A simple porcelain lavatory with oval bowl 



Fig. 37. Horizontal section of 

 a wooden, met-l-lined tank 



