68 DB. B. ANGUS SMITH ON ANCIENT AND 



found in them a very weak solution of decomposing matter. 

 Of this water there will probably very soon pass 20,000,000 

 gallons per day through the sewers of Manchester. This 

 makes a large stream, and collected it will be a small lake. 

 Such an amount of water it does seem preposterous to lift, so 

 as to cover land by irrigation. If this water were spread over 

 a portion of land equal to 15,000 acres, it would be immensely 

 to increase the rain fall. Now, the difference in fall of rain 

 in London and Manchester is only 12 inches in the year; yet 

 how very different is the climate ! True, however, the water 

 is not to be put on in dry weather, and it will therefore not 

 increase the number of wet days ; but it will increase the 

 amount of water, and we know that in that case the time of 

 drying the ground must be much greater. Also the manure 

 is of course weakened still more, and the great excess of water 

 acting rapidly upon it is apt to carry a good deal away. If 

 put on with no excess of water, and allowed quietly to be 

 absorbed into the soil, there is a provision of nature for 

 absorbing the impurities and returning the water clear, if not 

 perfectly pure. This might, I think, be effected more readily 

 by using stronger liquids during wet weather, allowing the 

 rain to dilute them. There would be also less to manage, less 

 apparatus and expense, and no change of climate, from the 

 enormous amount of liquid. The irrigation of land by 

 sewage water is warn^ly recommended by the Board of Health 

 in a very valuable report. If this water were not to be put 

 on as liquid manure, but to be treated by precipitation, a 

 plan which I think might succeed well, and be in many places 

 to be preferred, then it would be found much easier to 

 manage the liquid when concentrated. Used as liquid 

 manure in moist weather, we have all the advantages of very 

 dilute manure ; we have the proportion of dry and wet days 

 unchanged, and the state of moisture of the soil also unchanged 

 to any extent worth mentioning ; and as, wherever this liquid 

 is transported, water is transportable, we have the means alsq 



