Lamp

FIG. 1 is a first perspective view of a lamp showing my new design; FIG. 2 is a second perspective view thereof; FIG. 3 is a front view thereof; FIG. 4 is a rear view thereof; FIG. 5 is a left side view thereof; FIG. 6 is a right side view thereof; FIG. 7 is a top view thereof; FIG. 8 is a bottom view thereof; FIG. 9 is an enlarged view of a circled portion 9 of FIG. 1 ; FIG. 10 is another perspective view thereof, showing a light tube of the lamp in another position; FIG. 11 is another perspective view thereof, showing the light tube of the lamp in another position; FIG. 12 is another perspective view thereof, showing the light tube of the lamp in another position; and, FIG. 13 is another perspective view thereof, showing the light tube of the lamp in another position. The broken lines shown in the drawings depict portions of the lamp that form no part of the claimed design. The dot-dash broken lines in FIGS. 1 and 9 illustrate boundaries of enlarged views that form no part of the claimed design.