THE PINE-APPLE. / 



gutter, rising out of the flow-pipe at one end of the 

 house and dropping into the return at the other. I 

 have tried all these ways, and more besides, and con- 

 sider them all inferior to that represented by fig. 4. 

 This is a flat-bottomed open gutter or trough, 6 inches 

 wide, and 2J inches deep, running the whole length 

 of the house. In the centre and along the whole 

 length of the trough is fixed a rain-water or lead pipe, 

 2J inches in diameter. This, as will be seen, is con- 

 nected with the flow-pipe as it leaves the boiler, and 

 with the return-pipe at the other end of the house. 

 At the middle of the house a tap is fitted into the 

 2 J -inch pipe; a flow of water from the tap can be 

 so adjusted as to let water sufficient trickle into the 



FIG. 4. 



trough to keep it full and the small pipe nearly 

 immersed in water. The supply to the boiler being 

 by ball-cock, the small quantity of water that escapes 

 from the tap is constantly supplied. This apparatus 

 requires next to no attention, and heats regularly the 

 whole length of the house. In open gutters without 

 this small pipe, we have always found too much steam 

 at one end of the house and next to none at the other, 

 especially in long houses. The arrangement we recom- 

 mend is quite equal in heating power to a row of 

 4-inch pipe. When atmospheric moisture is not re- 



