with Reference to Sound. 29 
contrived so that the vitiated air may readily enough escape, 
without a corresponding loss of sound.* 
So intimately joined are the departments of ventilation and 
warming in their practical operation, that in treating of the former 
subject we have necessarily included, to some extent, the latter. 
onnected with the warming of a building, such as we are 
now considering, there are two points of practical importance 
that are mainly to be considered, viz: First the propriety of unit- 
ing the mechanical appliances for heating and ventilation in one 
and the same plan; secondly, the nature of the apparatus to be 
yak oe whether steam or hot water pipes, or the common 
urnace 
3 
within a few degrees of the point required when the audience 
are present, inasmuch as the entering current will not immedi- 
ately mix with air of a different temperature. To serve the pur- 
poses of a summer ventilation, or to allow the admission of cold 
ar, if required, without its passing across the heating apparatus, 
avery simple arrangement only is necessary. ; 
Concerning the second point, our preferences are decidedly in 
favor of the use of steam or the mild hot water apparatus, over 
every other system of which we have any knowledge. 
uestion of its greater expense, we conceive, should not be placed 
eside its manifold advantages. As we have not room now for 
the discussion of these points, we refer the reader to the able 
treatises of Tredgold and Arnott for a full exposition of the su- 
petior virtues of the plan we would adopt; suffice it for us to say 
here, that in this way, only, do we believe an agreeable, salu- 
— and equable atmosphere in a large room, can be made 
certain. 
'S hot unimportant. Here the same principles are to be kept in 
view that have been previously stated. In the ordinary methods 
of artificial lighting, whether from gas, oil, wax or tallow, the 
alr ot a room is rapidly contaminated and admixed with the va- 
* Saunders, in hi ise on theatres, recommends that these ventilators be 
wed during iiucaeemios of the yess and opened only between the acts. ‘This 
ever, is going to the opposite extreme. aos 
