250 



MACHINERY IN COXNECnON "WITH AIE. 



the top about a third less than the rest of the flue. The 

 Fig. 279. current at the moment of escape is swifter 

 than below, and less acted upon by any down- 

 ward blast of the wind, at the same time 

 that the surface is smaller on which the wind 

 can strike the current, as shown in fig. 278. 

 A chimney of this character may be very 

 easily made by contracting the tiers of brick, 

 thus giving to it an ornamental appearance, 

 as seen in lijx. 279.* 



* Where different fires communicate with the same chimney, separate 

 flues shoiild be built for each fire, and Ivcpt separate in the same chim- 

 ney-stacli, carried up independently of each other. But even with this 

 precaution, smol^y rooms will not be avoided, unless the termination of 

 the chimney is of the right form, of which the folloAving illustration is 

 given in Allen's Rural Architecture : 



"Fifteen years ago we purchased and removed into a most substantial 

 and well-built stone house, the chimneys of which were constructed 

 with open fireplaces, and the flues carried up separately to the top, 

 where they all met upon the snme level surflxce, as chimneys in past times 

 usually were built thus (fig. 280). Every fireplace in the house (and some 

 of them had stoves in) smoked intolerably ; so much so, that when the 

 wind was in some quarters, the fires had to be put out in every room 

 but the kitchen, which, as good luck would have it, smoked less al- 

 though it did smoke there than the others. After balancing the mat- 

 ter in our own mind some time whether we would pulldown and re- 

 build the chimneys altogether, or attempt an alteration as we had 



Fig. 281. 



given but little thought to the sub- Fig. 2S0. 



jcct of chimney draught, and to try 



an experiment was the cheapest 



we set to work a bricklayer, who, 



under our direction, simply built 



over each discharge of the several 



flues a separate top of fifteen inches 



high, in this wise : Fig. 281. The '^ 



remed}' M'as perfect. We have had no smoke in the house since, blow 



the wind as it may, on any and on all occasions. The chimneys can^t 



smoke ; and the whole expense for four chimneys, with their twelve 



flues, was not twenty dollars ! The remedy was in giving each outlet a 



distinct current of air all around, and ou every side of it." 



