Shaft 1 of the anemograph cup wheel rotates cam 2 through three worm gearing units, converting the rotation of the shaft into vertical displacement of pen 5 of the registering mechanism. The angular displacement of weathervane 5 is transmitted in a similar manner to pen 4. Ring a, rigidly attached to weathervane 5, is an end cam along whose lower working surface roller 6 rolls. When weathervane 5 turns, the vertical displacement of roller 6 is transmitted by a lever system to registering pen 4. Elongation or contraction of one of the wires 7 due to changes in ambient temperature is compensated for by the change in length of the other wire. Thus, variations in temperature do not affect the readings of the instrument.
$3260$CmL,M$