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POPULAR SCIENCE REVIEW. 
sitting-rooms the fresh air comes in at the windows and doors, 
and when no other arrangement exists, we are sure to have 
draughts more or less injurious, according to the size of the 
interstices, apertures, &c. The question of where to introduce 
the cold air has always been a vexed one with hygienists. Even 
now, it cannot be looked on as definitively decided. Some 
writers say, introduce it through the floor, as in the House of 
Commons; others suggest a middle point between floor and 
ceiling ; while the latest researches seem to show that the ceiling 
itself is the best point. Whether the air be introduced at the 
level of tne ceiling, or at a sufficient height above the door to 
prevent unpleasant draught, is, in our opinion, immaterial. 
The great points to be attended to are the distribution of the 
air by causing it to pass through an immense number of aper- 
tures, and the employment of adequate means to bring it to a 
suitable degree of temperature. In most of the existing ar- 
rangements for the introduction of fresh air into rooms, the 
mistake is made of using a few small apertures (Sherringham’s 
ventilators et id genus omne). Hence, we often find in the 
houses of persons who pride themselves on the perfect ventila- 
tion of their rooms, that these latter have abominable draughts, 
whose course is defined with the greatest nicety, and which 
often appear to select one’s ears as the most convenient 
medium of transit.* This production of keen, sharp draughts 
has been the opprobrium of nearly all the vaunted ventilators 
hitherto employed. The method suggested by M. Morin, a 
French savant, who has paid much attention to such questions 
as these, obviates in a great measure these defects. His plan is 
somewhat similar to that recommended 
by the Commissioners for Improving the 
Sanitary Condition of Barracks and Hos- 
pitals, so that a description of the latter 
will represent both. At the level of the 
ceiling a number of perforated bricks 
are introduced into the wall, the area of 
the aperture being in the proportion of 
1 square inch to every 60 cubic feet of 
the capacity of the room.f In order to 
prevent the discomfort which might arise from a down-draught 
from these openings, a cornice is so arranged as to cover them. 
PERFORATED ZINC CORNICE. 
* Such draughts recall the sailor’s saying, that he u didn’t mind a fresh 
sou-wester, hut he was blowed if he’d sit in the ‘wake’ of a key-hole.” 
t A room 25 feet long by 18 feet wide and 10 feet high would have a 
capacity of 4,500 cubic feet. Its apertures for entrance of fresh air would 
therefore be 4,500-r-60=75 square inches. How large an area compared 
with the apertures now occasionally found oyer our doors, and misnamed 
ventilators ! 
