Step 3: The second crisscrossed layer overlaps the first, and so on, each subsequent layer fastened (here with glue) to the chimney rings and trimmed.

Step 4: The tinted diagonal side strips brace the layers underneath them and soften the curvature.

Step 5: The base between the chimneys is reinforced with additional strips cut and placed as shown in drawing #3, the strips bracing the side diagonals as well. Note: strips at the bottom remain attached provisionally to permit last minute adjustments.