FIG. 1. is a perspective view of an instrument showing a first embodiment of our new and ornamental design;
FIG. 2 is an alternate perspective view thereof;
FIG. 3 is an alternate perspective view thereof;
FIG. 4 is an alternate perspective view thereof;
FIG. 5 is a rear elevation view thereof;
FIG. 6 is a front elevation view thereof;
FIG. 7 is a side elevation view thereof;
FIG. 8 is a side elevation view thereof;
FIG. 9 is a top plan view thereof;
FIG. 10 is a bottom plan view thereof;
FIG. 11 is a perspective view of an instrument showing a second embodiment of our new and ornamental design;
FIG. 12 is an alternate perspective view thereof;
FIG. 13 is an alternate perspective view thereof;
FIG. 14 is an alternate perspective view thereof;
FIG. 15 is a rear elevation view thereof;
FIG. 16 is a front elevation view thereof;
FIG. 17 is a side elevation view thereof;
FIG. 18 is a side elevation view thereof;
FIG. 19 is a top plan view thereof;
FIG. 20 is a perspective view of an instrument showing a third embodiment of our new and ornamental design;
FIG. 21 is an alternate perspective view thereof;
FIG. 22 is an alternate perspective view thereof;
FIG. 23 is an alternate perspective view thereof;
FIG. 24 is a front elevation view thereof;
FIG. 25 is a side elevation view thereof;
FIG. 26 is an opposite side elevation view thereof;
FIG. 27 is a top plan view thereof;
FIG. 28 is a perspective view of an instrument showing a fourth embodiment of our new and ornamental design;
FIG. 29 is an alternate perspective view thereof;
FIG. 30 is an alternate perspective view thereof;
FIG. 31 is an alternate perspective view thereof;
FIG. 32 is a front elevation view thereof;
FIG. 33 is a side elevation view thereof;
FIG. 34 is an opposite side elevation view thereof;
FIG. 35 is a top plan view thereof;
FIG. 36 is a perspective view of an instrument showing a fifth embodiment of our new and ornamental design;
FIG. 37 is an alternate perspective view thereof;
FIG. 38 is an alternate perspective view thereof;
FIG. 39 is an alternate perspective view thereof;
FIG. 40 is a front elevation view thereof;
FIG. 41 is a side elevation view thereof;
FIG. 42 is an opposite side elevation view thereof;
FIG. 43 is a top plan view thereof;
FIG. 44 is a perspective view of an instrument showing a sixth embodiment of our new and ornamental design;
FIG. 45 is an alternate perspective view thereof;
FIG. 46 is an alternate perspective view thereof;
FIG. 47 is an alternate perspective view thereof;
FIG. 48 is a front elevation view thereof;
FIG. 49 is a side elevation view thereof;
FIG. 50 is an opposite side elevation view thereof; and,
FIG. 51 is a top plan view thereof.
The broken lines illustrate portions of the instrument that form no part of the claimed design. The radiating lines illustrate the glow of the illumination emanating from the instrument. The radiating lines form a part of the claimed design.