A description of ventilators

whereby great quantities of fresh air may with ease be conveyed into mines, goals, hospitals, work-houses and ships, in exchange for their noxious air : an account also of their great usefulness in many other respects : as in preserving all sorts of grain dry, sweet, and free from being destroyed by weevels, both in grainaries and ships, and in preserving many other sorts of goods : as also in drying corn, malt, hop, gun-powder, &c., and for many other useful purposes, which was read before the Royal Society in May, 1741