HEATING. 65 



commended for the great energy they show in 

 endeavoring to adapt their apparatus to the 

 demands of the trade. Prices are so close that 

 every additional ounce of iron counts, and for this 

 reason it would seem to be the part of wisdom to 



22. House twenty-four feet wide; posts set and shed at 

 north end built first. 



simplify construction as much as possible. It is 

 a matter of theoretical calculation to determine 

 what each section will do when added to a boiler. 

 In practice, however, it is frequently found that 



