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138 Report of the Medical Officer of Health.
other inlet, but there was no nuisance caused by this to
the public. The proper remedy for this, in my opinion,
was to provide natural inlets of suitable size and in
suitable positions.
"I do not think that sufficient consideration has been
given to the fact that the exhaust fan in Messrs. Harrison
& Barber's is also a propulsion fan, and that it has
to force the air through a furnace for the purpose of
destroying the offensive effluvia.
"This obstruction lessens very greatly the theoretical
amount of work done by the fan, and as there
was no obstruction in the case of the inlet fans the result
was that the air in the chamber was in a state of compression
and escaped into the open air by any crevices or
open doors.
"With regard to the Report of the Departmental
Committee I have been unable to find in that Report any
reference to the double system, except in the case of
cleaning by benzole, where the conditions are very
different.
"The conclusions of this Committee in fact, support
my contention that exhaust fans with dirigible currents
are far the most satisfactory, both for the worker and for
the purpose of obviating any public nuisance.
"I would refer the Committee to page 40 (fourth
Section) which is as follows:—
"'It should clearly be noted that the incoming
air is not blown in through the air shaft H, but in
reality is sucked in by the operation of the fans Z Z;
for these powerful fans, having to derive all their
supply of air from that in the room, tend to set up a
partial vacuum, which can only be satisfied by means
of inlets of corresponding capacity; and inasmuch as
the inlets are purposely restricted to the channels
above described, all the air entering the building can