500 



WATER SUPPLY AND SEWAGE DISPOSAL 



paid much attention to the development of the art of plumbing. 

 In time, however, man again began to think of improving his 

 conditions for comfortable living. The reproduction of an old 

 woodcut (Fig. 307), shows the method of heating water in the 

 most fashionable hotels of London in the 18th century. The 

 water was pumped by hand into an attic tank. By means of 

 an iron pipe it was conveyed down again into the bottom of the 



wrought-iron, riveted boiler at the 

 back of the kitchen fireplace. 

 Here it became heated. A sec- 

 ond iron pipe, shown in the illus- 

 tration, extended from the top of 

 the boiler to the guests' rooms. 

 The weight of the column of cold 

 water forced the heated water up 

 to the guests' room whenever 

 needed. Thus to be able to have 

 hot water in one's room whenever 

 needed was considered to be a 

 great luxury (Art. 170, p. 145). 



588. Hot Water System in the 

 Modern Residence. Today no 

 modern residence is complete 

 without a supply of hot water. 

 In Fig. 307 it will be seen that one side of the boiler was heated 

 directly by the fire. In the modern residence, however, the 

 water is heated by circulating through a WATER-BACK or 

 WATER-FRONT in the kitchen range, or a HEATING COIL in the 

 furnace, or by circulating through a special heater supplied for 

 this particular purpose. 



When the heater forms the front plate of the firebox it is 

 called a WATER-FRONT; when it forms the back plate of the 

 firebox it is called a WATER-BACK. Figures 293 and 300 also 

 illustrate the usual manner of connecting the boiler with the 

 heater. The arrows in Figs. 293 and 308 show the direction of 

 flow of water. Explain why the water circulates as it does. 



FIG. 



307. The 1 8th century 

 hot water system. 



