134 Of the Management of Fire 



boiler ; but the brick walls by which they are defended 

 from the cold air are double, and the space between 

 them is filled with charcoal dust. 



The fuel burns at the hither end of the middle flue, 

 in an oval dish-grate ; and the flame running along in 

 this flue under the middle of the boiler to the farther 

 end of it, there divides, and returns in the two adjoining 

 flues. It then turns to the right and left, and, going 

 back again in the two outside flues to the farther end of 

 the boiler, goes out from under it there in two canals, 

 which, sloping upwards, conduct it to the flues of a 

 second boiler of equal dimensions with the first, where it 

 circulates, and warms the water which is designed for 

 refilling the first boiler. 



As these boilers are made of exceedingly thin sheet- 

 copper, and thin boilers are stronger to resist the effects 

 of the fire, and consequently more durable than very 

 thick ones, they both together cost much less than one 

 single boiler on the common construction ; and Mr. 

 Duffin, secretary to the Linen Board, who is a very 

 active, intelligent man, and is himself engaged in a 

 large concern in the bleaching business, showed me a 

 computation, founded on actual experiments which he 

 himself made with this new boiler, by which he proved 

 that the saving of fuel which will result from the gen- 

 eral introduction of these boilers in the bleaching trade 

 throughout Ireland will amount to at least fifty thousand 

 pounds sterling a year. 



In a laundry which* I fitted up in the house belonging 

 to the Dublin Society (and which is designed to serve as 

 a model for laundries for private gentlemen's families), 

 there are also two oblong square boilers, the one heated 

 by the fire, and the other by the smoke; and this smoke, 



