Figs. 1 to 9 show some of the various forms of vessels. Fig. 1, diameter, 130 mm. Fig. 2, diameter, 280 mm. Fig. 3, diameter. 130 mm. Fig. 4, height. 330 mm. Fig. 5. diameter, 105 mm. Fig. 6, diameter, 180 mm. Fig. 7. diameter, 150 mm. Fig. 8, diameter, 150 mm.