Image #159 (2.75" x 4.5"): "3-13-29. The closing bottom chord joint at L17! Member on left has slotted hole at pin."; Image #160 (2.75" x 4.5"): " Closing joint at L17! 4" slotted hole allows erection of closing chord at any temperature."; Image #161 (2.75" x 4.5"): "3-13-29 Progress."; Image #162 (2.75" x 4.5"): "3-3-29. Closing bottom chords in place.";Four 4.5" x 2.75" B/W photos numbered 159, 160, 161, 162