[645] 



NOTES ON VENTILATION. 



1. In designing a combined system of heating and ventilation for 

 public buildings, one of tbe main difficulties is to get a uniform 

 draught in all the ventilation flues leading from the different rooms. 

 Where, as frequently happens, some of the ventilation flues act and 

 others do not, the equable distribution of heat is interfered with, and 

 therefore it is all the more necessary when a building is to be well 

 heated and ventilated to see that both sets of flues, hot-air and foul- 

 air, shall act properly. The following plan, it appears to me, will 

 be attended with success when the building is heated by steam on 

 the indirect system, and there is an attic available. "When the hot- 

 air flues are in the inner walls, the ventilation flues should be in 

 the opposite or outside walls, and vice versa. In the former case, all 

 should be extended directly up until they connect with a large tin- 

 lined box riinning around the exterior of the attic and leading into a 

 ventilation shaft or chimney. On the bottom of this box and along 

 its whole length a large steam pipe should be laid so as to cross the 

 openings provided for the ventilation pipes. All joints and connec- 

 tions should be made tight, and the dimensions of the flues adjusted 

 in due proportions. When the ventilation flues are in the inner 

 walls a corresponding treatment can be adopted. 



2. It has also appeared to me that, to a limited extent at any 



rate, the ventilation of railway cars would be improved by taking 



the supply of fresh air, so as to avoid dust and smoke, from a point 



in front of the locomotive. A pipe could be extended from this point 



to any part of the train by means of rubber connections between the 



cars, and any excess of draft at the point of delivery of the fresh air 



could be reduced by means of check plates. Were it not for the 



admirable system of heating cars by means of hot water pipes, it 



might be worth while considering if the fresh air so supplied could 



not be first warmed by passing it over heated pipes in a special car 



near the locomotive. 



J. L. 



