Refuse Disposal and Sewage Purification. 27 



"There are three, and only three, ahernative methods for 

 the disposal of the Belfast sewage I believe, viz. : (i) irrigation ; 

 (2) the construction of a main sewer to Blackhead, or at all 

 events to some spot on the coast where the sewage would be 

 swept out to sea by the turn ocean tide ; and (3) chemical 

 treatment. 



" Of these three the conditions for the first are so unsuitable 

 that there is no chance of its being adopted, while the cost of 

 the second would, I understand, place it out of the question. 

 This leaves the third as alone within the range of practical 

 politics. If that is the case can anything be gained by a delay 

 in executing the necessary works and in immediately starting 

 some precipitation process ? 



"I do not think that the local conditions require any very 

 elaborate treatment of the sewage, because it is not a question 

 of running the effluent into a river or watercourse, but into a 

 shallow-sea lough, where a large aerating surface exists quite 

 sufficient, I believe, to cope with the dissolved organic matter 

 which would remain after the employment of any of the 

 present precipitation processes. 



" One of the chief advantages of the immediate adoption of a 

 precipitation process would be that the effluent could be run off 

 at any time of the tide, and not as at present (under the Main 

 Drainage Act) during a restricted interval which I am told 

 is impossible frequently. — Yours, &c., E. A. Letts." 



The Chairman then called for discussion, and said he would 

 ask Mr. John Macllwaine to open the discussion on Mr. 

 Chambers's able paper. 



Mr. MacIlwaine said they were much obliged to Mr. Chambers 

 for the most interesting paper he had read. He (Mr. 

 Macllwaine) could offer nothing but friendly criticism on the 

 paper. He knew something about combustion, and, judging 

 the paper from that part of the subject with which he (Mr. 

 Macllwaine) was familiar, he would say that the qther part was 

 all right. They owed a debt of gratitude to tlieir American 

 cousins for having, after twenty years' experience, brought 



