CHIMNEY. 634 CHIMNEY-SWIFT. neys are found in {;re:it variety of forms. Pre- vious to the Sixteenth Century many of them arc sliort, and terminated by a spire or pinnacle, having apertures of various shapes. These apertures are sometimes in the pinnacle, sometimes under it, the smoke escaping as from some modern manufacturing chinuiey-stacks, which are built in the form of an Egyptian obe- lisk. Clustered chimney-stacks do not appear until late in the Fifteenth Century, when they Becni to have been introduced simultaneously with the use of brick for this purpose. Each of the earlier clustered chinuieys consists of two flues which adhere to each other, and are not set separate, as afterwards was the practice. Eong after they were invented, and in use for other rooms, our ancestors did not generally introduce them into their halls, which, till the end of the Fifteenth or beginning of the Sixteenth Century, continued as formerly to be heated by a tire on an open hearth in the centre of the hall, the smoke escaping tlirough an opening in the roof known by the name of louvre. In many of the older halls in which chimneys exist they have evidently been inserted about this period. Next to their use in removing the waste gases and supplying the necessary draught for do- mestic ami other heating apparatus, the most important use of chimneys is in connection with steam-power plants and metallurgical fur- naces of manufacturing and smelting works; Chimneys for power and smelting plants are structures of considerable size and cost. They are built of masonry, usually brickwork, and of metal, usually sheet steel. One of the largest brick chimneys in the world is that of the power plant of the" Metropolitan Street Railway Com- ])any in New York City, and a description of it will give a veiy clear idea of the character of such structures as they were built at the end of the Nineteenth Century, This chimney is 353 feet high, with an internal diameter of 22 feet: weighs 8540 tons, and required 3,400,000 bricks for its construction. In building the foundations, which cover an area of about 85 feet square, the earth was removed to a depth of 20 feet below the power-house floor, and 1300 piles were driven to a depth of about 40 feet over the entire area. These piles were cut olf at a level of one foot above the top of the excava- tion bottom, and an immense concrete block was laid upon them 85 feet square and 20 feet thick. Smoke-Hues lead from the boilers to the chim- ney from opposite directions, and as there are three stories in the boiler-house upon which the boilers are installed, there are six large open- ings to the chimney, two on each of the three floors. The chimney is built of two concentric shells, and the outer shell is stiffened by twelve interior longitudinal ribs projecting radially toward the inner shell and having a clearance of % inch. The inner shaft has a constant diameter of 22 feet, and the outside dimensions of the chinmey range from a square base 55 feet on a side to a cylindrical neek 20 feet 10 inches in diameter. 3ifi feet above. The inner shell varies from 24 inches thick at the base to 8 inches thick at the top. and is lined with 8 inches of fire-brick for a heiglit of 90 feet, and Avith 4 inches of fire- brick for 25 feet more: above this height the shell is not lined. The outer shell is 28 inches thick at the base and Ifi inches thick at the top. The top of the chimney is protected by a cast-iron cap. As an example of steel chimneys, that for the Kidgewood pumping station of the Brooklyn, N. v., water-works may be selected. The height of this chinuiey from the ground is 217 feet, the minimum diameter is 8 feet, and the diameter at the base is 25 feet. It is lined with brick for one-half its height. There are 137 plates in the structure, varying in weight from 800 to 1400 l)ounds, and in thickness from % inch to 'L- inch. The plates are of open-hearth steel, having a tensile strengtli of 05.000 |)Ounds per square inch. The chinmey was erected in ten weeks, the work of erection being performed from an inside scatl'old- ing which was raised as the work progressed. This chimney cost about $10,000. The following table gives the location. material, height, and diam- eter of some of the highest chinmevs in the world : LOCATION Height (t. Smallest diameter ft. Material 225 279 225 2G0 HUM. 350 488 45* 33tlA 367 V4 306 13% 11 9 (t. 10 ins. 11 13(t. liDB. 13 Jt. 4 ins. Steel I.eC'n-usiit, France Sparrows Point. Md.. Danvin & Mostyu Iron ('o., England Mechernieh, Colog-ne.... Fail River, aiaas Wrouiiht Iron Steel Brick Port Dundee, Glasgow. Townsend, " TiMinant ifc Co., "
13 (t. 2 ins. Stune Huddersfleld, England Brick CHIMNEY - SWALLOW. (1) In North America, the chimney-swift (q.v. ). (2) In the Old World, the familiar house-swallow (Hiruiido ruslica), which ranges eastward into western Cliina, where it is replaced by another species (llirundo gutturalis) . Several African swallows belong to this group, as also does our barn-swal- low (([.v.), wOiich English writers sometimes call, unfiutunatcly. the American chimney-swallow. CHIMNEY-SWIFT. The small, sooty, swal- low-like bird, connnonly but mistakenly called a 'swallow,' which throngs about chimneys in all parts of North America, and represents an almost cosmopolitan family. (See Swift.) It is mi- gratory, spreading northward into Labrador and the Fur Countries in early summer, and escap- ing in winter to Central America. Supported upon narrow wings, each an inch longer than its total lengtli ( about five inches ) from beak to tail, it spends its time almost continuously in the air, rarelj^ if ever alighting except inside the hollow tree or chimney where it liv<'S. and ceaselessly pursuing, oiien-mouthed, the minute insects upon which it lives, catching all of them on the wing, and doing us an important service. It even gathers in this way the materials for its nest, grasping with its feet tiny dead twigs pro- jecting from lofty tree- branches, snapping them ofT and bearing them away, without a pause in its fiiglit. Before the civiliza- tion of the country, as yet in remole districts, it in- habited hollow trees, some- times for hundreds of gen- erations in succession, attaching its nest to their interior wall; but as soon as houses were built. Clilmne.v-Switt. showing spines at end of tall- teathers.
