THE PATH TO NEW INVENTIONS.

[Chap. 21.

S54

it will descend the pipes, and enter the stove to bewarmed again: this may be done in very cold weather.The higher the room above the stove, the more power-fully will the warm air ascend and expel the cold air.But if the room require to be ventilated, the air must beprevented from descending, by shutting the little gate2 or 5, and drawing 1 or 6, and giving it liberty to as-cend and escape at A or G—or up the chimney, lettingit in close at the hearth. If the warm air be conveyedunder the floor, as between 5—6, and let rise in severalplaces, with a valve at each, it will be extremely conve-nient and pleasant; if above the floor, as at 4, several per-sons might set their feet on it to warm. The rooms willbe moderately warm throughout—a person will not besensible of the coldness of the weather.

One large stove of this construction may he made towarm a whole house, ventilate the rooms at pleasure,bake bread, meat, &c.

These principles and improvements ought to be con-sidered and provided for in building.

EXAMPLE V.

Art of Hulling and Cleaning Rice.

Step I. The principles on which this art may hefounded, will appear, by taking a handful of rough rice,and rubbing it hard between the hands—the hulls willbe broken off, and, by continuing the operation, thesharp texture of the outside of the hull (which, througha magnifying glass, appears like a sharp, fine file, and,no doubt, is designed by nature for the purpose) willcut ofF the inside hull, and the chaff being blown out, willleave the rice perfectly clean, without breaking any ofthe grains.

II. What is the best plan, in theory, for effecting this?(See the plan proposed, represented in Plate X., fig. 2;explained Art. 103.)