FIG. 1 is a front perspective view of a first embodiment of the firebox.
FIG. 2 is a back perspective view of FIG. 1.
FIG. 3 is a front plan view of FIG. 1.
FIG. 4 is a back plan view of FIG. 1.
FIG. 5 is a right plan view of FIG. 1.
FIG. 6 is a left plan view of FIG. 1.
FIG. 7 is a top plan view of FIG. 1.
FIG. 8 is a bottom plan view of FIG. 1.
FIG. 9 is a front perspective view of a second embodiment of the firebox.
FIG. 10 is a back perspective view of FIG. 9.
FIG. 11 is a front plan view of FIG. 9.
FIG. 12 is a back plan view of FIG. 9.
FIG. 13 is a right plan view of FIG. 9.
FIG. 14 is a left plan view of FIG. 9.
FIG. 15 is a top plan view of FIG. 9.
FIG. 16 is a bottom plan view of FIG. 9.
FIG. 17 is a front perspective view of a third embodiment of the firebox.
FIG. 18 is a back perspective view of FIG. 17.
FIG. 19 is a front plan view of FIG. 17.
FIG. 20 is a back plan view of FIG. 17.
FIG. 21 is a right plan view of FIG. 17.
FIG. 22 is a left plan view of FIG. 17.
FIG. 23 is a top plan view of FIG. 17.
FIG. 24 is a bottom plan view of FIG. 17.
FIG. 25 is a front perspective view of a fourth embodiment of the firebox.
FIG. 26 is a back perspective view of FIG. 25.
FIG. 27 is a front plan view of FIG. 25.
FIG. 28 is a back plan view of FIG. 25.
FIG. 29 is a right plan view of FIG. 25.
FIG. 30 is a left plan view of FIG. 25.
FIG. 31 is a top plan view of FIG. 25.
FIG. 32 is a bottom plan view of FIG. 25.
FIG. 33 is a front perspective view of a fifth embodiment of the firebox
FIG. 34 is a back perspective view of FIG. 33.
FIG. 35 is a front plan view of FIG. 33.
FIG. 36 is a back plan view of FIG. 33.
FIG. 37 is a right plan view of FIG. 33.
FIG. 38 is a left plan view of FIG. 33.
FIG. 39 is a top plan view of FIG. 33.
FIG. 40 is a bottom plan view of FIG. 33.
FIG. 41 is a front perspective view of a sixth embodiment of the firebox.
FIG. 42 is a back perspective view of FIG. 41.
FIG. 43 is a front plan view of FIG. 41
FIG. 44 is a back plan view of FIG. 41.
FIG. 45 is a right plan view of FIG. 41.
FIG. 46 is a left plan view of FIG. 41.
FIG. 47 is a top plan view of FIG. 41.
FIG. 48 is a bottom plan view of FIG. 41.
FIG. 49 is a front perspective view of a seventh embodiment of the firebox.
FIG. 50 is a back perspective view of FIG. 49.
FIG. 51 is a front plan view of FIG. 49.
FIG. 52 is a back plan view of FIG. 49.
FIG. 53 is a right plan view of FIG. 49.
FIG. 54 is a left plan view of FIG. 49.
FIG. 55 is a top plan view of FIG. 49.
FIG. 56 is a bottom plan view FIG. 49.
FIG. 57 is a front perspective view of an eight embodiment of the firebox.
FIG. 58 is a back perspective view of FIG. 57.
FIG. 59 is a front plan view of FIG. 57.
FIG. 60 is a back plan view of FIG. 57.
FIG. 61 is a right plan view of FIG. 57.
FIG. 62 is a left plan view of FIG. 57.
FIG. 63 is a top plan view of FIG. 57.
FIG. 64 is a bottom plan view of FIG. 57.
FIG. 65 is a front perspective view of a ninth embodiment of the firebox.
FIG. 66 is a back perspective view of FIG. 65
FIG. 67 is a front plan view of FIG. 65.
FIG. 68 is a back plan view of FIG. 65.
FIG. 69 is a right plan view of FIG. 65.
FIG. 70 is a left plan view of FIG. 65.
FIG. 71 is a top plan view of FIG. 65.
FIG. 72 is a bottom plan view of FIG. 65.
FIG. 73 is a front perspective view of a tenth embodiment of the firebox.
FIG. 74 is a back perspective view of FIG. 73.
FIG. 75 is a front plan view of FIG. 73.
FIG. 76 is a back plan view of FIG. 73.
FIG. 77 is a right plan view of FIG. 73.
FIG. 78 is a left plan view of FIG. 73.
FIG. 79 is a top plan view of FIG. 73.
FIG. 80 is a bottom plan view FIG. 73.
FIG. 81 is a front perspective view of an eleventh the firebox.
FIG. 82 is a back perspective view of FIG. 81.
FIG. 83 is a front plan view of FIG. 81.
FIG. 84 is a back plan view of FIG. 81.
FIG. 85 is a right plan view of FIG. 81.
FIG. 86 is a left plan view of FIG. 81.
FIG. 87 is a top plan view of FIG. 81.
FIG. 88 is a bottom plan view of FIG. 81.
FIG. 89 is a front perspective view of a twelfth embodiment of the firebox.
FIG. 90 is a back perspective view of FIG. 89.
FIG. 91 is a front plan view of FIG. 89.
FIG. 92 is a back plan view of FIG. 89.
FIG. 93 is a right plan view of FIG. 89.
FIG. 94 is a left plan view of FIG. 89.
FIG. 95 is a top plan view of FIG. 89.
FIG. 96 is a bottom plan view of FIG. 89.
FIG. 97 is a front perspective view of a thirteenth embodiment of the firebox.
FIG. 98 is a back perspective view of FIG. 97.
FIG. 99 is a front plan view of FIG. 89.
FIG. 100 is a back plan view of FIG. 89.
FIG. 101 is a right plan view of FIG. 89.
FIG. 102 is a left plan view of FIG. 89.
FIG. 103 is a top plan view of FIG. 89.
FIG. 104 is a bottom plan view of FIG. 89.
FIG. 105 is a front perspective view of a fourteenth embodiment of the firebox.
FIG. 106 is a back perspective view of FIG. 105.
FIG. 107 is a front plan view of FIG. 105.
FIG. 108 is a back plan view of FIG. 105.
FIG. 109 is a right plan view of FIG. 105.
FIG. 110 is a left plan view of FIG. 105.
FIG. 111 is a top plan view of FIG. 105.
FIG. 112 is a bottom plan view of FIG. 105.
FIG. 113 is a front perspective view of a fifteenth embodiment of the firebox.
FIG. 114 is a back perspective view of FIG. 113.
FIG. 115 is a front plan view of FIG. 113.
FIG. 116 is a back plan view of FIG. 113.
FIG. 117 is a right plan view of FIG. 113.
FIG. 118 is a left plan view of FIG. 113.
FIG. 119 is a top plan view of FIG. 113.
FIG. 120 is a bottom plan view of FIG. 113.
FIG. 121 is a front perspective view of a sixteenth embodiment of the firebox.
FIG. 122 is a back perspective view of FIG. 121.
FIG. 123 is a front plan view of FIG. 121.
FIG. 124 is a back plan view of FIG. 121.
FIG. 125 is a right plan view of FIG. 121.
FIG. 126 is a left plan view of FIG. 121.
FIG. 127 is a top plan view of FIG. 121.
FIG. 128 is a bottom plan view of FIG. 121.
FIG. 129 is a front perspective view of a seventeenth embodiment of the firebox.
FIG. 130 is a back perspective view of FIG. 129.
FIG. 131 is a front plan view of FIG. 129.
FIG. 132 is a back plan view of FIG. 129.
FIG. 133 is a right plan view of FIG. 129.
FIG. 134 is a left plan view of FIG. 129.
FIG. 135 is a top plan view of FIG. 129.
FIG. 136 is a bottom plan view of FIG. 129.
FIG. 137 is a front perspective view of an eighteenth embodiment of the firebox.
FIG. 138 is a back perspective view of FIG. 137.
FIG. 139 is a front plan view of FIG. 137.
FIG. 140 is a back plan view of FIG. 137.
FIG. 141 is a right plan view of FIG. 137.
FIG. 142 is a left plan view of FIG. 137.
FIG. 143 is a top plan view of FIG. 137.
FIG. 144 is a bottom plan view of FIG. 137.
FIG. 145 is a front perspective view of a nineteenth embodiment of the firebox.
FIG. 146 is a back perspective view of FIG. 145.
FIG. 147 is a front plan view of FIG. 145.
FIG. 148 is a back plan view of FIG. 145.
FIG. 149 is a right plan view of FIG. 145.
FIG. 150 is a left plan view of FIG. 145.
FIG. 151 is a top plan view of FIG. 145.
FIG. 152 is a bottom plan view of FIG. 145.
FIG. 153 is a front perspective view of a twentieth embodiment of the firebox.
FIG. 154 is a back perspective view of FIG. 153.
FIG. 155 is a front plan view of FIG. 153.
FIG. 156 is a back plan view of FIG. 153.
FIG. 157 is a right plan view of FIG. 153.
FIG. 158 is a left plan view of FIG. 153.
FIG. 159 is a top plan view of FIG. 153; and,
FIG. 160 is a bottom plan view of FIG. 153.
The broken line showing is included for the purpose of illustrating portions of the article and forms no part of the claimed design.