188 REPORT OF THE HORTICULTURIST OF THE 
give greater strength and durability than the square form that 
has generally been employed. In order to facilitate computations, 
the area inclosed within the cylinders was designed to represent 
as nearly as possible one ten-theusandth part of an acre (28.26-+- 
inches in diameter). The wood-work was ordered to be made so 
that the inside diameters of the cylinders should be 283 inches. 
It was found, however, that after the copper lining had been put 
in, the actual diameter was a fraction less than 28! inches. The 
error was doubtless due to shrinking of the staves, which were 
not very dry when the cylinders were made. The desired area 
will be secured by soldering a copper hoop, of the exact diameter 
required, to the top of each cylinder. 
Each lysimeter was made of 22 white oak staves of equal width. 
These were cut from plank 23 inches thick, but in order to form 
sufficient taper to hold the hoops they were dressed down from 
the center to 1} inches thick at each end. A section is shown 
at A A in the drawing. The bottoms were made of two inch 
white oak plank. In the two cylinders that were filled with sur- 
face soil, the bottom was set in a gain, cut about the inside of the 
cylinder, two inches from the lower end. In the other two, it 
was made of a diameter corresponding to that of the outside of 
the cylinder, as in the drawing, and was fastened in place with 
iron clamps, after the cylinders were filled. 
The cylinders were lyed with sheet copper. For the first 
twenty inches down from the top, the grade known in commerce 
as “18-ounce” (supposed to weigh 18 ounces to the square 
foot) was used. . Below this the ‘‘14-ounce” grade was used. It 
was assumed that the chief danger of breakage of the lining 
would occur near the surface of the soil, where the changes of 
temperature are greatest, and where the ground freezes hardest; 
hence a heavier grade of copper was used in this part. 
The two cylinders filled with soil “in place” were sunk about 
the columns of soil by excavating on the outside and dressing 
down the column to fit the inside of the cylinder. For the latter 
work, a mason’s trowel was found very serviceable. In the first 
one filled, which was the shorter one, a cask was set on the top of 
the cylinder and the first soil removed was put into this, to form 
a weight, to assist in settling the cylinder. This, however, proved 
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