No. XXXVI.C.] APPENDIX. 405 



in tke interest of all concerned, be approved by an independent public 

 officer. The nature of tlie ground to be irrigated is of importance, for it 

 is necessary for successful irrigation that the sewage should pass com- 

 pletely into the ground. Any place which is waterlogged is not suitable ; 

 and even at the Croydon sewage-ground water lies on an average within 

 two or three feet from the surface of all parts of the sewage farm. Again, 

 care should be taken that in the choice of a situation underground channels 

 capable of dii-ectly conveying the sewage to distant parts should be avoided ; 

 for example, chalk strata have cracks probably of nules in length, having 

 an imeven characteiv The cracks or fissui-es vary in width from a hair's 

 breadth to a width of nine or ten inches, and if sewage were turned into 

 one of these fissures it might reappear some miles off. The question of 

 these fissui-es, which exist all round London, opens up very serious con- 

 siderations, as the watei" is liable to contamination from cesspools. The 

 importance of the subject has attracted the attention of engineex's, and 

 may possibly be the subject of a paper at some futiu-e period. The 

 employment of a sewage-ground without the approval of a public officer 

 should be forbidden under a penalty of at least £50 a day. 



At the present time parts of the sewage-gi-ound actually employed for 

 irrigation frequently abut on the propei'ty of neighbouring proprietors, 

 which is greatly damaged. It is also frequently abutting on the highway. 

 I have heard it given in evidence before a committee of the House of Lords 

 that a sewage-ground was so near suburban villas, that the inmates played 

 at croquet upon the very verge of the pestilential marsh so created, a state 

 of things which should be rigidly prevented. At Beddington, I have often 

 seen the irrigation carried to the very verge of the high road, or beside the 

 property of neighbouring landowners. Now not less than 200 yards should 

 intervene between the part irrigated and any highway or adjoining pro- 

 perty, under a penalty of not less than £10 a day. The interval of 200 

 yards is by no means sufficient under all circumstances to fully protect 

 the public from the abominable stench and pestiferous effluvia of sewage- 

 grounds, though it would afford very substantial relief from the emana- 

 tions whenever the atmosphere possessed am average state of diffusive 

 powei". Li calm " muggy " evenings the distance will be manifestly 

 insufficient, and therefore should be increased wherever practicable. The 

 nuisance committed by the emanations of a sewage-gi'ound vaiies every 

 day, and at every hour of the day, with the atmosphere. In a clear bright 

 day, with wind and a rapid motion of the air upwards, it is reduced to a 

 minimum. In evening and morning with slight haze and stillness it is 

 increased to a maximum. 



At the time I was wi-iting the work ' My Gai-den,' I was examining 

 historical remains on the sewage-grounds. I was there one evening (when 

 only one irrigation had taken place") j the ground had dried, and the grass- 

 seed was sown, and yet the stench at sundown was so intolerable that we 

 were glad to leave the place. I have also been at the sewage-grounds during 

 frost, and even then the exhalations were most offensive and disagreeable. 



The fact is, that unless the sewage is defecated before in-igation, a 

 layer of faecal mattei- is deposited on the surface of that part of the ground 

 which has no crops upon it ; and if there are crops, the f cecal matter is 

 deposited upon the plants growing upon it. For this reason sewage 

 irrigation cannot be practised without creating a nuisance, except by 



