48 Suggestions for a System of 



continued over these, and the foot communication rendered 

 perfect, and yet the necessary water channel be preserved. 

 Of course the communication with the channels down Collins- 

 street would be by curved junction pipes of similar dimen- 

 sions, commencing at another 15 feet from the angle of 

 intersection of the kerbing. I am aware that covered drains 

 have been tried before, but I am also aware that they were 

 simply enlarged specimens of the defective construction of 

 house drains already alluded to. When it is remembered 

 that it has been proved by actual experiment that a three-inch 

 pipe drain is more efficient than a nine-inch brick barrel 

 drain, it will be probably conceded that the failure re- 

 ferred to affords no argument against the plan here suggested. 



I now come to the great question, the sewerage of the city 

 itself and the employment of a system of underground drain- 

 age for that piirpose. My views may probably be met by a 

 reference to the costly and complex systems that have been 

 in operation at home ; and it may be said that their failure 

 should operate against the adoption of analogous schemes 

 here. To this I reply, that we are not compelled to adopt 

 their failures, but that we can benefit by their improvements ; 

 and, with your permission, I will now endeavor to show, as 

 briefly as possible, the causes of those failures which we 

 should avoid, and the nature of those improvements which 

 it would be wise to adopt. I may, however, remark, that 

 all the evils attributed to the old world system are not equal 

 to a tithe of those that would have followed — and in all cases 

 did follow — where drainage was altogether ignored. 



One evil in the old system was the employment of sewers 

 for carrying off surface water as well as house drainage. 

 From this cause large quantities of silt found their way into 

 the drains, gradually choking them up. In localities liable 

 to sudden and frequent storms there existed the further 

 objection that sewers adequate to the requirements of the 

 ordinary drainage were burst by the rapid accumulation and 

 consequent pressure of storm waters. Hence, in any efficient 

 system, separate provision is requisite for surface drainage 

 and for house sewerage. 



But a greater and more prolific source of mischief in the 

 old world system, as it existed about ten years since, was to 

 be found in the form of the sewers, both large and small. 

 The main sewers were generally of large size — five feet six 

 inches high and three feet wide ; the top arched over, the 

 sides perpendicular, the bottom a portion of a very flat seg- 



