CHIMNEY. In modern English houses chimney-flues are often formed within the substance of the party-wall,leaving the width and projection of the jambs entirely to rho taste of the architect ; and, where two adjci s ing houses are built with the fire-places back to back, two sets of fines are introduced in the same party-wall. Where this is not done, the flues are carried up in the projecting jambs, which are necessarily made large. In some of the best houses all the flues are so constructed as to be swept from openings in the basement story, without entering the rooms into which the fire-places open.
The chimneys, flues, or stalks, (as they are often termed) of our great chemical works, are among the most remarkable examples of construction. The gaseous exhalations from such works are so noxious, that an attempt is made to discharge them into the atmosphere at as great a height as possible; and a great height also increases the draught of the fur naces below. Hence the enormous chimneys which have been constructed within the last few years. Cotton factories have also occa sionally chimneys of enormous height. At Messrs. Dewhirst's factory, at Manchester, a chimney has lately been built 243 feet high; it has a circular shaft, resting on a rectangular base 21 feet square by 45 feet high ; and is wholly built of stone, of which it contains 1,700 tons. The chimney to Messrs. Dixon's cotton factory, at Carlisle, is 305 feet high ; and it is octangular, and built of brick with stone angles. The chimney to Messrs. Mus pratt's chemical works at Newton is 397 feet high. At Messrs. Blinkhorn's chemical works near Little Bolton is a chimney 368 feet high ; it consumed in its construction 800,000 bricks and 120 tons of stone. The chimney at the great St. Rollox chemical works, near Glasgow, is 430 feet high, 50 feet in diameter at the foundation, 40 feet at the level of the ground, and 14 feet at the top. It has an inner chimney, disconnected from the outer, 260 feet in height by 16 feet in diameter. This fine chimney, being on a hill, forms a fine object for many miles ; but it has needed repairs of a very troublesome and difficult hind. A great chimney was finished at Wigan
in 1847, after four years of construction, iu connexion with an extensive chemical work. it exceeded 400 feet in height. Almost im mediately after its completion, an indentation was observed near the top, and an eminent engineer of Manchester recommended the removal of a portion of the top. About 80 feet was thus gradually removed ; but the base continued to sink and displace during this period, until at length the whole pOnder ous structure fell in one mass, and stretched its huge mass 'across the Leeds and Liverpool Canal.
The chimney belonging to Messrs. Cubitt's building establishment at Pimlico, is aremark able one. An attempt has been here made to give architectural character to that which is too often unsightly. The chimney shaft is entirely enclosed within a square tower, which presents much the appearance of an Italian campanile. The shaft is circular, 120 feet high, 5 feet internal diameter, and varying in thickness from 14 to 8 inches. The square tower envelopes the shaft without touching it. The upper portion of the tower, besides a belfry and a clock-room, affords space for a capacious cistern, useful in many exigencies. These advantages, and a saving of fuel from the shaft being kept shielded from the ex ternal cool air, are considered to pay an ample return for the increased outlay, inde pendently of the architectural ornament thus produced.
The chimneys or flues connected with some of our mines are more remarkable than any yet described. At the great Cwnz Avom mining and smelting works in South Wales, a chimney has been built at the top of a mountain; and flues are carried up the sides of this mountain from the works below to the chimney above. At the Tamer lead mine, on the confines of Cornwall and Devon, a steam engine has lately been set to work at a depth of 800 feet below the level of the river Tamer ; and in order to give an outlet for the smoke of this engine, flues extend from it, in horizontal galleries and vertical shafts, like a flight of steps, until they reach the surface on the opposite side of the river. This united flue is nearly two miles in length.