To prove this we have only to refer to reports made by engineers during the last fifteen years on drainage schemes, compare the results of the theories laid down, and note the instances in which they have failed, especially those in connection with sewage farms and the ventilation of sewers.
I will quote a few extracts from these reports:—
“No injury to health can possibly take place from gas issuing from properly constructed gratings fixed in the middle of the road, and if one is a nuisance, dig down and put in others until the nuisance is removed.”
This has certainly not been the case. You may dig as many holes as you like, and put in as many gratings, yet some will be injurious to health.
In describing sewage farms, they were described as being (if adopted) the means of securing a large revenue to the Local Board by the excellent crops grown, one engineer stating that persons could walk through them with as much pleasure as through a flower or kitchen garden; but practical experience has proved this to be incorrect: and although these statements were made in good faith, they have not been realised.
You may regulate the irrigation of a sewage farm to such a nicety that no odour from the sewage is perceptible in the district; yet the atmosphere will contain poisons which will have a very detrimental effect on the health of those living there.
For a few years after sewage farms have been laid out, they pay, and you get good crops from them, but after that the ground becomes so soured that the farm is almost useless.
In face of these facts no surveyor should hesitate to bring forward known improvements to his Board.
Many owners of property have recognised the importance of adopting the best sanitary measures for their houses, although in some cases it is only a plea to let or sell their property. As an instance of this, some time ago I was in search of a house in the suburbs, and met with one described as standing on good gravelly soil, with good drainage and perfect sanitary arrangements. The builder and owner took me over the house, and on reaching the kitchen pointed out with some degree of pride that the sink was cut off from the drains, and stated that the drains were constructed on the most “scientific principles.”
Now although scientific plumbers have done good work in making our dwellings more healthy, they have in many cases overdone the matter. The fact of their displaying conspicuously, on signs and billheads, “Sanitary work executed on the most scientific principles,” is not always a guarantee that a healthy house can be received from their hands.