38 
level with the adjacent surface or a little above, as otherwise the 
line is likely to be bridged by dust and rubbish blown upon it. The 
effectiveness of the barrier depends, indeed, largely upon the prep- 
aration of the strip of earth along which the tar is to be poured. 
Such a path was prepared in six different ways on as many sections 
of the line. 
Beginning at one end, a strip ten rods long was prepared beside 
the fence by simply scraping smooth with a hoe and sharp spade. 
Where the ground is hard, and grass and weeds form a thick mat, 
one man will not ordinarily clear over five rods an hour. This 
method is laborious and expensive, and would only be necessary 
where a team could not be used. It would cost for labor about two 
cents a rod. 
The second section of ten rods was prepared by plowing two 
very shallow furrows with a fourteen-inch plow, merely skimming 
away the weeds, grass, and surface roots. Both these furrows 
threw the dirt towards the wheat field, leaving a belt about two 
feet wide free from weeds and grass, and separated from the wheat 
by the dirt thrown over. The work was thus done rapidly, but by 
this method the bare strip is left lower than the general surface and 
is liable to be covered in places with dust and weeds by the wind. 
It must also be smoothed here and there with a hoe before the tar 
is laid down. Eighty rods can be prepared in this way by one man 
and a single horse in half a day. 
The third section of ten rods was made ready by plowing a 
back furrow in the stubble and beating the ridge of earth flat and 
hard with spades. This was one of the most satisfactory of the 
methods used, as by it the tar line is placed on a ridge where it is 
not likely to be bridged either by winds or rains. The comparatively 
loose earth will at first absorb the tar more freely than the hard bot- 
tom of a furrow, but this difference is not noticeable after a few 
days. A ridge of this kind may be more rapidly prepared by using 
an inverted trough-like drag of planks, weighted if necessary, to 
compact the earth, as has been done in Kansas on a large scale. 
This will take, for an eighty-rod line, the work of a man and team 
for about half a day. 
The fourth ten-rod section was prepared by plowing a very shal- 
low furrow with a single horse along the edge of the grass in the 
headland next the fence, throwing the dirt upon the stubble. This 
was not a satisfactory operation, however, as it left too narrow 
a smooth surface. 
The fifth section, forty rods in length, was prepared by simply 
scraping away the weed and grass roots as clean as possible with an 
