Heart, 357. Veins, 358; capillary, 358; pulmonary, 361. Ventral segments, 291. Ventricles, 357. Vibration of columns of air on oblique surfaces--The balloon--The flying-machine 322 Chapter XVIII.--HYDRAULIC MACHINERY. The siphon--The bucket pump--The force-pump--The most marvellous facility. The New-York solar salt exhibited at Rochester could not now.