LOOKOUT MOUNTAIN-LOOM.

GLASS (see-MIRROR). LOOK-OUT, a small watch-tower, or an elevation, on the roof of a building; a view; a prospect; watch.

LOOK-OUT MOUNTAIN, Battle of: see CHATTANOOGA, BATTLEe of.

LOOL, n. lôl: a vessel used to receive the washings of ores in mining districts.

LOOM, n, lôm [AS. geloma, or loma, utensils, household stuff: Gael. làmh, a hand or handle]: literally, a utensil, or a tool; a simple machine in which cloth is woven-the one set of threads running lengthwise in the material being called the warp, and the other set running across being called the woof or weft; the part of an oar lying within the boat when rowing. HAND-LOOM, a loom wrought by the hand. HEIR-LOOM, see HEIR. POWER-LOOM, a loom wrought by steam. JACQUARDLOOM, jak-kârd-, or zhǎ-kârd'-, a machine invented by M. Jacquard of Lyons for weaving figured goods.

LOOM, v. lom [Icel. ljóma, to gleam, to shine: It. lume, light: AS. leoma, a ray of light, a beam]: to be seen imperfectly, as a ship on the horizon, or seen through a mist; to appear indistinctly above the surface either of sea or land; to appear larger than the real size, and indistinctly; to appear to the mind's eye faintly or obscurely, or, as it were, in the distance. LOOMING, imp.: N. the indistinct appearance of a distant object, as in a mist, or particular state of the atmosphere. LоOMED, pp. lômd.

LOOM.

LOOM: machine by which weaving is effected. The art of weaving is coeval with civilization, therefore the L. may be reckoned among the earliest of man's inventions; yet, notwithstanding its vast age, very little improvement was effected in it until the invention of Dr. Cartwright 1787, who, without ever having seen a L., constructed one to work by machine-power. In its simplest form, the L. is worked by hand; and notwithstandthe wonderful improvements which have been effected in the power-loom since its invention, many fabrics still are manufactured by hand-looms.

In India, probably the native country of the L., and where silks of almost unrivalled beauty are made, the natives continue to use this machine in its most primi

tive form; two trees growing near together form their standing frame, and a few pieces of bamboo, together with some pieces of string, furnish all they want besides.

The principle of weaving shows the work that the L. has to do. In its simplest sense, weaving consists in passing one set of threads transversely through another set, divided into two series, working alternately up and down, so as to receive the transverse threads in passing, and interlock them, forming thereby a united surface out of the threads. The L. is made to assist the weaver in this operation in the manner shown in fig. 1: AAAA is the frame, and is of no other use than to hold the working-parts in their proper position. The native of

LOOM.

India supplies this usually by selecting two near-growing tree-stems, usually palms, because of their straightness: these, with four stakes to support his warp, and two or three pegs to fix his heald-ropes, complete his arrangements.

At each end of the frame, two rollers are placed, B, C, so that they will readily turn on their axes; and from one to the other, the threads of the warp are attached, and kept tight by the weights b, b. The warp-threads are wound round the roller B, which is called the bear

Fig. 2.

or yarn-roll, only as much of each thread being left un wound as will reach to the other roller, C, which is the cloth-beam, to which the ends are fastened, and upon which the cloth is wound as it is woven. The warp so stretched is seen in fig. 2.

The next step is to divide the warp-thread into two equal sets by raising up every alternate one, and inserting between them a smooth rod of wood, to prevent

Fig. 3.

them entangling or returning to their former position. This separation takes place before the final fixing of the ends of the threads to the cloth-beam, because, previous to that, each thread must be passed through a small loop in a perpendicular thread called the heald, which hangs down from the rod A in fig. 3 (in which only six heald-threads and six warp-threads are shown, for the sake of rendering the action clearer). are always two sets of healds in the simplest form of L., often many more; and in the case of plain weaving the threads of the warp are divided alternately by the, loops of each heald, so that if one heald is raised, it

There

LOOM.

lifts every alternate thread of the warp, and if the other is depressed, it pulls down the opposite set of threads; thus, in fig. 3, the three threads of the warp are seen to pass through the three upraised threads of one heald by the loops a, a, a, and the three remaining threads of the warp pass through the depressed healds by their loops b, b, b; the united action of the two healds opens a space between the two sets of warp-threads similar to that shown in fig. 4. This space is called the shed, and through it is thrown the shuttle which carries the thread of the weft; when the weft has passed through, the healds

Fig. 4.

are reversed, and the lower warp-threads now become the upper ones. The threads, after each intersection, are driven up tight by the reed, which is a narrow frame with transverse wires set sufficiently far apart for a single thread of warp to pass through each; it hangs to the frame called the batten, fig. 1, D. The movement of the batten is produced by the hand of the weaver, while that of the healds is readily effected by the treadles E.

Many improvements have been made in this the simplest form of L., but the chief has been in replacing the weaver's hand in the necessary operation of throwing the shuttle by a mechanical arrangement. Without this, the power-loom would not have succeeded. The shuttle (fig. 5) is usually made of box or some other hard-wood; and the blunt points are covered with iron. Formerly, when used entirely by the hand, it was made much lighter and smaller than at present. Those now in use are about 12 inches in length, and rather more than an inch square in the middle. The middle part is hollowed into a small box, open on the upper side. In this box the bobbin, on

Fig. 5.

which the yarn or thread is wound, is placed, with its two ends on pivots, admitting of its being turned by the slightest strain on the yarn; the end of the yarn passes through a hole in the side of the shuttle, as seen in fig. 5; and as it is thrown forward and backward, the thread unwinds from the inclosed bobbin, and easily runs through the hole.

In the improved looms for power, and even in those still worked by hand, in special cases the arrangement for projecting the shuttle forward and backward is very

LOOMIS.

simple. On each side of the L., exactly in a line with the shed, is a groove of about 18 inches, in which the

shuttle lies free; and there is a very simple arrangement by which a piece of leather and a strap are made to act like a sling on each side; and the grooves or shuttle-races, as they are called, guide the movement with such precision that the shuttle is sent flying through the shed from side to side with unerring exactness. This arrangement is shown in fig. 6. The simplicity and compactness now attained in the power-loom, allow three to stand in the space occupied by one of the cumbrous machines formerly in use.-See WEAVING.

LOOMIS, lo'mis, ELIAS, LL.D.: 1811, Aug. 7-1889, Aug. 15; b. Willington, Conn.: educator. He graduated at Yale 1830; was tutor in science there 1833-36, during which time he began observing the altitude of shooting stars and the declination of the magnetic needle, and discovered the return of Halley's comet; studied in Paris 1836-37; and was prof. of mathematics and nat. philosophy in Western Reserve College 1837-44. During 1844-60 he was professor of natural philosophy in the Univ. of the City of New York, and prepared most of his well-known mathematical and astronomical text-books. In 1860 he became Munson prof. of nat. philosophy and astronomy in Yale College, where he remained till his death. He received the degree LL.D. from the Univ. of the City of New York 1854, and bequeathed his books and pamphlets relating to mathematical and physical sciences, and the bulk of his estate, estimated at $300,000, to Yale College to aid original research in its observatory. His publications include Plane and Spherical Trignometry (1848); Progress of Astronomy (1850,56); Analytical Geometry and Calculus and Elements of Algebra (1851); Elements of Geometry and Conic Sections (1851,71); Tables of Logarithms (1855); Natural Philosophy (1858); Practical Astronomy (1855,65); Elements of Arithmetic (1863); Treatise on Meteorology (1868); and Elements of Astronomy (1869).