, a 
ee ee! eek ee 
’ 
152 JOHN M. SMAIL. 
rainwater pipe finished in close proximity to an attic or other 
window. The window is left open on warm nights to enable the 
occupant to sleep in comfort, the gas escaping from the hopper 
head finds its way into the room and vitiates the air, this is inhaled 
by the sleeper, until in time if still exposed to such insanitary 
surroundings, his system becomes completely sapped. This is the 
condition of numerous dwellings in Sydney at the present day; 
the number however is being gradually reduced as the public are 
becoming alive to the fact that sewer gas is not a thing that one 
would like to be on intimate terins with. 
In later years work has been carried out by the City Corporation 
on more modern principles, the house drain being cut off from the 
sewer and provision made for ventilation, this however the Council 
had no power to enforce and was only carried out in comparatively 
few instances. 
The work of the shaft in Hyde Park from a trial extending 
over six hundred and forty-eight hours was 40°853 cubic feet per 
hour, this is due to natural ventilation only. Observations are 
being taken along the different sewers to determine the limit of 
efficiency. 
New system of sewers.—The new system of sewers carried out 
by the Government and transferred to the Board has intercepted 
the older sewers at certain points, and the gases formed in them 
are carried by the sewage into the new system, thus complicating . 
the work of ventilation. These however will gradually be super- 
seded by smaller and deeper sewers which will admit of ventil- 
ation and aeration being carried out with facility.’ Shortly after 
completion of one of the main branches of the Bondi outfall some 
of the manholes were tested with test papers of a 10°/ solution of 
acetate of lead, and on being forwarded to the Government Analyst 
(Mr. Hamlet, F.1.c., F.c.s.) he reported in one case that the test 
paper indicated an amount of hydrogen sulphide decidedly danger- 
ous to health; this gentleman also fixed a comparative scale by 
which it could be ascertained from test papers whether the sewer 
air was dangerous to health or otherwise. 
