i8 79 .] 



HEATING BY HOT WATER. 



527 



number of compartments without sinking the boiler more than 1 foot 

 below the floor on which the main body of the piping is laid. 



a, Boiler ; B, Main flow-pipe, rising above the door-tops against the 

 back wall, enclosed in a wooden case filled with sawdust ; C, Branch 

 pipe, carried over door-top from main flow and attached in the usual 

 way to the pipes D for heating the compartment ; E, Main re- 

 turn-pipe, running the full length of the range a few inches below 

 the floor -level. The dotted line is the supposed ground -level. 

 The branch pipes over doorways to be covered with ornamental 

 grating, or otherwise ornamented to correspond with the woodwork 

 of the houses. 



In this form of the hot- water apparatus Mr Pearson thinks air would 

 be troublesome. Well, I do not underrate the resistance offered by 

 air to the circulation of the water through the pipes ; but in this form 



the heated air will get to the highest point by a shorter route than it 

 does in the form in general practice. In the latter form the air finds 

 its way to the highest points, and provision is there made for its escape. 



In the form represented by the accompanying figure the air will also 

 find its way to the highest points, and the usual means for its exit 

 from the pipes will be provided. And if Mr Pearson has nothing of a 

 more solid nature than air bubbles to offer in opposition to this form, I 

 have no doubt of being able to prevent any obstruction that they, 

 through their aerial nature, may be disposed to offer to the free circula- 

 tion of the water through the apparatus. 



Mr Pearson next says : " If the houses were built for the pipes, and 

 not the pipes for the houses, he would let the water rise the whole way 

 until it is about to re-enter the boiler." In reference to this statement, 

 might I presume to ask Mr Pearson if he is ready to stake his reputa- 



