On Socket Drain-Pipes. 
603 
or injure the soil in succeeding years, I cannot but fear that they tend to 
mislead many readers. 
To which of these two classes do Nitrate of Soda and Sulphate of Am- 
monia belong? That is a question which I am myself unable to answer : 
but it is possible that some of the Members of the Council may be able 
to answer it; and if so I should be very thankful for such information. 
With regard to Guano, looking at its reported origin and its chemical 
composition, one can scarcely doubt that it enriches the soil ; but its 
very caustic quality may raise a question whether a part of its beneficial 
effect does not arise from its stimulating properties. If so, its value can- 
not surely be truly estimated by comparing the increase of crop yielded 
by Guano and by yard-dung. 
How might this question be brought to the test? Might it not be 
done hy dressing a piece of land heavily, year by year, with Guano or 
other of these new manures ; applying no dung to it, and cropping it in 
the usual manner If the manure under trial operates as a stimulus 
merely, the land would be found, under this management, to grow pro- 
gressively poorer every crop : if, on the contrary, it operates as nutriment, 
the land would grow progressively richer. But perhaps this experiment 
has already been tried. 
I am, dear Sir, 
Very truly yours. 
East Leigh, Emsworth, John Barton. 
Aug. 13, 1844. 
XIV. — On Socket Drain-Pipes. 
To the Secretary. 
Dear Sir, — When I had the pleasure of meeting you at ]\Ir. F. Hobbs's 
I promised to send you some specimens of socket drain-pipes, as I 
make them in my yard. They are applicable particularly to loose 
springy soils, and cannot fail to be safe. Some persons prefer holes to 
be made in pipes ; but they appear to me to be in all cases unnecessary. 
These pipes may be made of any length — the most convenient and use- 
ful is probably from 15 to 18 inches; and the cost of the socketing by 
the machine (I use Ford's jjatent) is from 2^. 6c?. to 3^. 6rf. per thou- 
sand. I have enclosed with the pipes a curious evidence of the facility 
with which the roots of trees will destroy drains, if carelessly placed. 
The mass of fibres are the roots of a willow-tree, growing about 5 or 6 
feet from the drain, which had been put down only twelve months, and 
the pipe from which I took it was a four-inch socketed' one. 
I am sorry that thin one-inch pipes find advocates ; they have no 
recommendation but cheapness, and must fail. In my judgment, as 
well as in that of many experienced diainers here, no pipe should have 
a less bore than 2 inches in the clear ; and, in many cases, even for 
surface-draining, it should be larger ; and it should possess substantial 
thickness, to give it durability. 
On Wednesday last, so soon as the heavy rain of that day ceased, I 
