474 
Journal of Agricultural Research 
Vol. XXIV, No. 6 
In February, 1921, the writer { 4 ) offered the theory that concrete tile 
were liable to disintegration in any soil carrying a high percentage of 
organic matter. This was followed in July of the same year by a further 
statement (5) to the same effect. 
In addition to the authorities quoted, numerous observers in the last 
two years have reported a breaking down of concrete tile lines in soils 
high in organic matter. None of the authorities quoted, however, either 
in this country or Europe, have followed up their observations with 
exhaustive research which they have later reported. Nor have any of 
them considered it probable that concrete tile would break down in soils 
carrying a high percentage of lime. Consequently in the work covered 
by these investigations, this point has been especially recognized and 
covered. 
university marsh 
A tract of no acres of peat marsh is located on the experimental farm 
of the University of Wisconsin. For the past 10 years this land has 
been used for experimental purposes in drainage. This area, which at 
one time was a swampy bay of Take Mendota, is generally known as 
University Marsh. Most of its surface is a little above the lake and the 
soil consists of fibrous peat 2 to 6 feet deep, underlain by sand and clay. 
In the deeper parts of the marsh there is a bed of marl between the peat 
and the mineral soil below. The marl bed varies considerably in thickness 
up to a maximum of about 18 inches, and around its margin frequently 
blends with, and is interlaid by sand. Since diking, various types of 
drainage have been worked out, improvements and changes being made 
as their value was demonstrated. 
On the higher side of the marsh are a number of high morainal hills 
from which the surface water of about 400 acres drains down. Heavy 
seepage also works into it from below, expecially in the sandy portion. 
This is sufficient if the stream is concentrated into a pipe to lift the water 
2 % feet above the marsh surface. 
From the beginning, this experimental work on the marsh has been un¬ 
der-the direction of E. R. Jones, professor of agricultural engineering at 
the University of Wisconsin and State drainage engineer. During the 
fall of 1919, and the season 1920, the work was under the direct charge 
of the writer, whose principal function was a determination and compila¬ 
tion of data on the physical change in the marsh brought about by the 
various stages of drainage and cultivation. 
Part of the work consisted of an examination of the tile lines themselves. 
This was done by groups, taking as a group a series of tile having a 
common outlet and laid at the same time and under similar conditions. 
On each group several pits were dug for the purpose of examination. If 
no unusual conditions were disclosed, it was assumed that none had 
developed. If, however, any unusual condition were disclosed, more pits 
were dug for the purpose of determining whether or not the unusual 
conditions were inherent in the group. 
DISINTEGRATED TIDE 
Seven lines of tile, two of which were concrete, were laid by students 
in May and June, 1914. Lines 5 and 7 were of concrete. In December, 
1919, on opening these two lines, the tile were found to show signs of 
failure. 
