As each mirage class is described, you must keep in mind that the description also applies to each category, and to a wind from right (3 oâclock) or from the left (9 oâclock).The first class to be considered is the boiling mirage, with heat waves rising vertically as in(Fig 3).slow mirage) to 4 to 7 m.p.h. wind is applied, the rear sight must be lowered 1 Â¼ minutes and Â¾ minute windage added for horizontal component of the mirage. During the string, the mirage picture changes from heavy-slow to heavy-medium which signals the increase in wind velocity.