Furnace

FIG. 1 is a perspective view of a furnace showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is an partially enlarged view of the encircled area 8 in FIG. 1 ;

FIG. 9 is an partially enlarged view of the encircled area 9 in FIG. 1 ; and,

FIG. 10 is an partially enlarged view of the encircled area 10 in FIG. 2 .

The showing of evenly broken lines is for illustrating portions of the article that form no part of the claimed design. The dot-dash lines represent boundaries of the enlarged portions and form no part of the claimed design.