240 
TO MEASURE THE HEIGHT OF STANDING TREES. 
Irrigation — Vertical Section. — Fig. 66. 
TO MEASURE THE HEIGHT OF STANDING TREES. IRRIGATION.— No. 2. 
A correspondent of yours, at Fond du Lac, in ; Sometimes situations occur at the foot of hills, 
the current volume of the Agriculturist; inquires or along the borders of streams, where the land 
whether " you or any of your readers can give is flat, or nearly level, and the modes described 
a description of an instrument for taking the at pp. 216, 218, of the current volume, for dis- 
height of trees while standing." ' tributing the water, cannot be applied, for the 
There are two simple methods which I have want of a sufficient declivity to allow the water 
seen practised in France, and which, though to pass rapidly over the surface. In such cases, 
they may be well known and familiar to many, the whole field should be laid out into broad 
I have never seen described, nor used in this beds, 60 or 80 feet wide, undulating, as it were, 
country. One is, when a tree is isolated, or like the waves of the sea. The central or upper 
with a space around it sufficient to see its top part of these beds, or panes, should be made 
without interruption, the height is taken by mea- j quite level from end to end, through each of 
suring it by an angle of 45 degrees from the J which a channel, or "float," a, a, should be 
eye, or in other terms, by making the tree one cut for conducting the water from the feeder,/, at 
of the sides of an imaginary right-angled trian- the higher side of the meadow, as indicated by 
gle. To do this, take a thin piece of board, say Fig. 67 in the diagram below. 
4 feet long by 6 inches in width, jointed perfectly From the edge of these channels, the surface 
straight on one of its edges. 
At one extremity of this board, 
an exact square of 6 inches 
is traced by black or white 
lines, to the upper angle o 
which a small plumb is 
suspended by a line of a 
foot in length. The opera- 
tor then puts the straight 
line of the board to his eye, 
walks backward from the 
tree to the point of distance, 
when the eye, running along 
the line of the board, strikes 
exactly the extremity of the 
top, at the same time that 
the line of the plumb passes 
exactly through the upper 
and lower points of the 
square traced on the lower 
end of the- board and from 
the point where he then 
stands, the distance to the 
foot of the tree adding thereto 
the height of the operator 
from his feet to his eyes and 
one half the diameter of the 
tree, is its true height. 
Another method still more 
expeditious and simple is 
used by measuring the shad- 
ow of the tree when the sky 
is perfectly clear and there 
is no interruption to its shade 
stick of 6, 8, or 10 feet in length ; place it per- 
pendicularly on the earth by a plumb line ; and 
make an exact measurment of the shade it 
casts upon the ground; then measure the length 
of the shadow of the tree with equal exactness, 
and as the length of the shade of your rod is to its 
length or height, so is the length of the shadow of 
the tree to its height. A Traveller. 
Gunpowder for Choked Cattle. — Make a 
cartridge large enough for a musket and thrust 
it down the throat; if that does not produce re- 
lief, repeat the charge; or, if the choking is so 
bad that this will not relieve it, you may use 
fire with the powder with the next charge. 
Irrigation — Ground Plan. — Fig. 67. 
Take a rod or of the ground should be made to slope, from 
one to two feet, both ways from the centre, and 
ditches, or drains, d, d, d, cut at the bottom, be- 
tween the beds, parallel with the " floats." 
These beds should not be curved like the ridges 
of a plowed field, but form inclined planes from 
the centre to each side. The floats are supplied 
by a main channel, or feeder,/, at right angles 
to the beds, elevated somewhat above them, 
and all the ditches or drains, d, d, d, should be 
made to run into another main ditch, or waste 
drain, w, at the lower side of the field, parallel 
to the feeder/ By this arrangement, the course 
of the water will be very regular. As soon as 
the " stops," or flood gates are opened, it flows 
into the floats, or upper channels, until they are 
full to the brim, when thev will overflow the 
