CHIMNEY-CAPS. 



255 



Fig. 275. 



Fig. 276 is 



Fig. 2T6. 



has no influence. In this case, the caj) represented hj fig. 

 275 furnishes a complete remedy, and is, in- 

 deed, perfect in its operation under any cir- 

 cumstances whatever, for the chimney sur- 

 mounted by it will always draw when there 

 is wind from any quarter, with or without a 

 fire. It has effected a perfect cure in some 

 chimneys which before were exceedingly 

 troublesome, and were regarded as incurable, 

 intended to show the mode of its 

 operation ; the wind, as shown by 

 the arroAVS, being deflected for a 

 considerable distance on the lee 

 side, SO as to form a vacancy at a, 

 which the wind from the other end 

 and from the chimney both rush in to supply. Being 

 fixed on without turning in the chimney, it is both simpler 

 and less noisy than any caps furnished with a vane. 



Emersoii^s Chimney-cap is different in construction, 

 Fig. 277. but quite simi- 



lar in principle 

 to the preced- 

 ing. It is shown 

 by fig. 277. A 

 sheet-iron pipe 

 is set in the top 

 of the chimney, 

 iiiiiii-iiiiiiiiiiiiiiiiliiillil furnished with 

 the conical rim, and a plate 

 or fender on the top, which ex- 

 cludes the rain. Between the 

 plate and rim is a space quite 

 similar in form or section to 

 that represented by fig. 276. 

 In exposed situations, chim- 

 neys are found to draw more uniformly by contracting 



Flflr. 2' 



