254 



SHEET-METALWORK 



221. Laying Out Conical Shapes. The pattern for a 

 cone or for a frustum of a cone is made by describing an arc of 

 a circle with a compass or a pair of dividers, the distance be- 

 tween the points being the slant height of the cone and the 

 length of the outside arc being circumference of the base of 

 the cone. 



222. Construction of Funnel. Lay out the pattern 

 for each of the two parts of the funnel (Fig. 290), producing the 



FIG. 291. Piece of wood for shap 

 ing funnel. 



side lines of front view to locate 

 the apex of each cone part, in 



order to secure the radius to 

 FIG. 290. Metal cu* for funnel. strikethe proper arcg (Fig . 290) . 



As in the case of the cylindrical part of the cup, insert a 

 1/16" wire in the space marked 1/4" on the outside of the 

 large pattern, and fold in opposite directions the laps for the 

 lock seam joints. Carefully form each portion of the funnel 

 over a cylindrical piece of stove wood tapered on one end to a 

 cone (Fig. 291). Lock and solder the joint for each part, slip 

 the upper part into the lower, first spreading out the upper 

 opening of the lower part over the surface of the cone-shaped 

 piece of wood, and solder the two parts together. The ear 

 may be made as shown in Fig. 286, and a small piece of wire 

 formed to slip into it to form a hanger. The ear may be sol- 

 dered on or fastened with rivets. 



