FIG. 1 is a perspective view of the sight glass of my new design;

FIG. 2 is a front elevational view thereof; the rear elevational view is a mirror image thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is sectional view taken along line 7—7 of FIG. 2; and,

FIG. 8 is a sectional view taken along the line 8—8 of FIG. 5.