LAMP SHADES p.191
except where it joins the sections of the shade. It is pierced on the sides to allow the heat to escape, as there are four lights under the shade. The rivets that fasten the angles in place are smooth,
Fig. 122. Shade with Drop Sides
the holes in the angles being countersunk. The stock for angles is No. 18, while the sections of the shade are No. 20. As there is no pierced work in the shade the angles are made from heavier stock, adding strength to the shade.
Fig. 122 shows another kind of lamp shade, with drop sides. The sections and sides are of one piece of stock. The corners are fastened in the same manner as previously explained. Copper cleats are used to fasten the glass.
Hand Forging by Thomas F. Googerty