PROCEEDINGS OF THE SECTIONS. 345 
adoption of the system, and before the practice can be made 
universal, an amended Act will be required conferring such power 
on the Council. 
It will not necessarily be requisite to erect such a pipe to every 
house, in order that the pressure in the sewer should be relieved, 
as some buildings are too low to secure proper ventilation ; but if 
a pipe-shaft (say) of 5 or 6 inches diameter, be affixed to most of 
the loftier buildings, a sufficient vent would be secured. 
A building now being erected by Mr. Alex. Dean for Dr. 
M‘Laurin in Bligh-street, is an excellent example of the way in 
which these principles are to be applied. 
any other premises are similarly fitted, and these, as well as 
securing safety for their occupiers, help to relieve the sewers from 
undue pressure of gas. 
The interceptor trap is on the same principle as that known as 
Buchan’s, a sanitary plumber of Glasgow, and is a thoroughly well- 
considered device, combining adaptability to its functions with 
ease of access for repairs. 
The New Zealand Insurance Offices in Pitt-street and several 
other buildings are ventilated by a different method, which dis- 
penses with traps, trusting to the constancy of the upeast draught 
in the ventilating shaft exhausting the air in the pan and chamber. 
is method is adopted by Mr. Woodford, plumber, of Charlotte- 
street, and with success in every instance that I have examined. 
lithograph herewith how desirable and even how indispensable it 
is to intercept the poisonous gases—in a manner that they shall 
