AETIFICIAL HEAT AND APPARATtJS. 



43 



veyed around the house in a flue, which almost nullified 

 the improved principle ; but of late years a great improve- 

 ment has been accomplished, so much so as to make it 

 almost perfect. After having been acquainted with nearly- 

 all kinds, I have not found any to give so much satisfaction 

 as those constructed on the cone principle, of which fi<^. 11 

 is a longitudinal section, and fig. 12 an external view of 

 the latest and most improved plan ; and, notwithstanding the 

 progressiveness of science, I do not, at present, see how this 

 iri to be superseded. It is made and to be obtained from 



' -t5?^f^. -Plor 11 iL^^^i^^ Fig. 12. 



Weathered & Oherevoy, of 117 Prince street, New York, 

 and is decidedly more economical and better than the one 

 figured in the first edition of this book. The boiler is a 

 double casing,, between which and the internal connections 

 the water is contained. It occupies very little room, and 

 requires no masonwork whatever; the stand for the boiler 

 being made of cast-iron, which forms the ash-pit underneath, 

 and a chimney or pipe to convey away the smoke. This 

 apparatus, when completed, with pipe four inches in diame. 

 ter, will cost from $1 to %\ 25 per lineal foot on the meas- 

 ure of th*» pipe, and a house forty feet long for early forcing 

 would need about two hundred feet, so that reckoning tho 



