The design consists of features of the shape, configuration and ornamentation of the Tachometer as shown in the drawings in which:FIG. 1 is a perspective view of a first variant of the Tachometer;FIG. 2 is a front elevational view of the first variant of the Tachometer;FIG. 3 is a rear elevational view of the first variant of the Tachometer;FIG. 4 is a left side elevational view of the first variant of the Tachometer;FIG. 5 is a right side elevational view of the first variant of the Tachometer;FIG. 6 is a bottom elevational view of the first variant of the Tachometer;FIG. 7 is a top elevational view of the first variant of the Tachometer;FIG. 8 is a perspective view of a second position of the first variant of the Tachometer;FIG. 9 is a front elevational view of the second position of the first variant of the Tachometer;FIG. 10 is a rear elevational view of the second position of the first variant of the Tachometer;FIG. 11 is a left side elevational view of the second position of the first variant of the Tachometer;FIG. 12 is a right side elevational view of the second position of the first variant of the Tachometer;FIG. 13 is a bottom elevational view of the second position of the first variant of the Tachometer;FIG. 14 is a top elevational view of the second position of the first variant of the Tachometer;FIG. 15 is a perspective view of a second variant of the Tachometer;FIG. 16 is a front elevational view of the second variant of the Tachometer;FIG. 17 is a rear elevational view of the second variant of the Tachometer;FIG. 18 is a left side elevational view of the second variant of the Tachometer. The right side elevational view of the second variant (not shown) is a mirror image of the left side elevational view;FIG. 19 is a bottom elevational view of the second variant of the Tachometer;FIG. 20 is a top elevational view of the second variant of the Tachometer;FIG. 21 is a perspective view of the third variant of the Tachometer;FIG. 22 is a front elevational view of the third variant of the Tachometer;FIG. 23 is a rear relational view of the third variant of the Tachometer;FIG. 24 is a left side elevational view of the third variant of the Tachometer. The right side elevational view of this third variant (not shown) is a mirror image of the left side elevational view;FIG. 25 is a bottom elevational view of the third variant of the Tachometer;FIG. 26 is a top elevational view of the third variant of the Tachometer;FIG. 27 is a perspective view of a fourth variant of the Tachometer;FIG. 28 is a front elevational view of the fourth variant of the Tachometer;FIG. 29 is a rear elevational view of the fourth variant of the Tachometer;FIG. 30 is a left side elevational view of the fourth variant of the Tachometer. The right side elevational view of the fourth variant (not shown) is a mirror image of the left side elevational view;FIG. 31 is a top elevational view of the fourth variant of the Tachometer;FIG. 32 is a bottom elevational view of the fourth variant of the Tachometer;FIG. 33 is a perspective view of a second position of the fourth variant of the Tachometer;FIG. 34 is a front elevational view of the second position of the fourth variant of the Tachometer;FIG. 35 is a rear elevational view of the second position of the fourth variant of the Tachometer;FIG. 36 is a left side elevational view of the second position of the fourth variant of the Tachometer. The right side elevational view of the second position of the fourth variant (not shown) is a mirror image of the left side elevational view.FIG. 37 is a bottom elevational view of the second position of the fourth variant of the Tachometer;FIG. 38 is a top elevational view of the second position of the fourth variant of the Tachometer;FIG. 39 is a perspective view of a fifth variant of the Tachometer;FIG. 40 is a front elevational view of the fifth variant of the Tachometer. The rear elevational view of this fifth variant (not shown) is the same as shown in Figure 29.FIG. 41 is a left side elevational view of the fifth variant of the Tachometer. The right side elevational view of this fifth variant (not shown) is a mirror image of the left side elevational view.FIG. 42 is a bottom elevational view of the fifth variant of the Tachometer; andFIG. 43 is a top elevational view of the fifth variant of the Tachometer.Drawings of the design are included.