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works the pinion, on the axle of which are placed two 
fingers, one live and the other dead. These fingers move 
according to the pressure given (or movement of the pinion), 
and thus the force is shown by looking at the dial plate, and 
the figure to which the live finger points shows the present 
force of the wind, whilst the dead finger is opposite the 
figure, showing the maximum pressure that the wind has 
attained during a given period. This is effected by a small 
pivot or pin at the point of the dead finger projecting above 
the live one, so that as the live finger is forced by the pres- 
sure it carries the other with it, and leaves it at that point 
if the wind decreases. In front of the spring in the space 
already referred to is a small disc attached to a rod, on 
which is placed a wind plate of six inches square. This 
plate is kept to the wind by a vane on the opposite side of 
the circular box, and as its area is just one fourth of a 
square foot, the graduated dial figures being multiplied by 
four gives the same result as though the plate were a foot 
square. This size of plate gives lightness, and reduces the 
friction to a minimum. The working parts of the instru- 
ment are protected from the weather by a glass lid or cover. 
Having thus described the anemometer proper, which 
shows the force of the wind, I will describe how it makes 
self-records in a permanent form, and shows the range and 
direction of the wind at the same time. A pencil is at- 
tached to the movable rod holding the pressure plate, and 
moves backward and forward with the plate. The point 
of the pencil, which is vertical, rests on the paper, and 
whilst it has the lateral motion referred to it moves in a 
circular form, as the anemometer moves with the wind. 
The papers, which are 10 inches in diameter, fit into a 
horizontal recess, placed below the rod about two inches 
under the anemometer. These papers can be changed daily, 
and measured by a prepared scale, and thus are permanent 
records of the force, range, and direction of the wind. If 
