hay, A c the stroke of the ram. and c b the final depth of
the bale of hay. The curve a m F j D is the curve of pres-
sures per square inch of pumps drawn out to a scale making
c D equal to A c. This curve is ascertainable from Table
X. Complete the square a c D e, and join E c, cutting
the curve in f, and draw the vertical f g, then f g represents



PRESSES FOR BALING, ETC. 21 5

the pressure per square inch at which the larger pump must
trip. This pressure being known, the combined area of the
two pump plungers can be fixed such that the total available
power is absorbed at this pressure. The size of the smaller
plunger being already fixed, the larger is ascertained by
subtraction.
If three pump plungers are to be used, the pressures at
which the two larger must trip can be found by drawing the
diagonals l m, h j so that the area of the square A c D e is
divided into three equal parts, or



from which a l may be found. The diagonals l m, h j
having been drawn, the verticals m n, j k give the pressures
at which the pumps must trip. The sizes of the plungers
are now ascertained by finding the combined area of the
small and medium plungers, at the pressure j k, to absorb
the maximum available power, from which area the size of
the medium plunger is found, as before, by subtraction.
In the same way the combined area of the three plungers
is found for the pressure M n, and the size of the largest
ascertained by subtracting the combined area of the other
two.
