These knots are of two classes, the Ghiordes and the Sehna. The Ghiordes are found in all rugs of Asia Minor and Caucasia, in some of the rugs of India, and in most of the rugs of Persia. They are named after the town of Ghiordes in Asia Minor, where some of the finest Asiatic pieces were made, and which tradition states was once the ancient Gordion, noted even in the days of Alexander. In tying the knot, the two ends of yarn appear together at the surface included between two[6] adjacent threads of warp around which they have been passed, so that the tighter the yarn is drawn the more compact the knot becomes. The three different ways of tying this knot are shown in Plate [B], Figs. 1, 2, and 3 (Page 49), of which the second is known as a “right hand” and the third as a “left hand” knot. The Sehna knots, which are used in the Turkoman, Chinese, many of the Persian, and in some of the Indian rugs, take their name from the city of Sehna in Persia. In tying them, a piece of yarn encircles a thread of warp and is twisted so that its ends appear at the surface, one at each side of the adjacent thread of warp, as is shown in Plate [B], Figs. 4, 5, and 6. According as this thread of warp is to the right or the left of the one they encircle, the knots are known as “right-hand” or “left-hand” knots,[7] but in the appearance of the carpet there is no distinction. If the pile of a rug is carefully parted, the two ends of yarn forming a Sehna knot can be separated; but with the Ghiordes knot this is impossible, as will be understood by studying Plate [B], in which Figs. 1, 2, 3, 7, 8, and 9 are Ghiordes knots, and Figs. 4, 5, 6, and 10 are Sehna knots. As a rule, the Sehna knots, which permit of closer weaving and clearer definition of pattern, appear in rugs of shorter nap.
Plate B.—Nos. 1, 2, 3, 7, 8, 9, Ghiordes knots. Nos. 4, 5, 6, 10, Sehna knots. No. 11, Weft-overcasting. No. 12, Double-overcasting. No. 13, Weft-selvage. No. 14, Double-selvage. Nos. 15, 16, 17, illustrate one, two, and three threads of weft passing between two rows of knots.
The nice distinctions in the technique of weaving are rarely understood even by those who are familiar with Oriental rugs. The general pattern, which next to colour is the characteristic that most quickly arrests the attention, is often the sole guide by which novices guess the class. The more experienced will observe if the knot be Ghiordes or Sehna, and examine the finish at the sides and ends; but few give the peculiarities of the weave the consideration they deserve. This, perhaps, is because only those who have made a special study would believe the constancy with which members of a tribe or locality have followed the same method of tying the knot and inserting the weft. The different methods of treatment by separate tribes are sometimes only slight, but they afford a most important clue for determining the place of origin of doubtful classes. In fact, nearly every class has a typical weave differentiating it from all other classes. To be sure, there are exceptions to the established type which are inevitable; since, for instance, a man from the Feraghan district might marry a woman from the adjoining Hamadan district, who, to please her husband, might weave a rug with pattern common to his district but follow the style of weaving that she has been familiar with from childhood. Nevertheless, weavers of a particular district adhere more closely to a typical style of weaving than they do to any other characteristic of a rug. Nor is this surprising, since weaving is learned in earliest childhood; and as it contains no elements calculated to stimulate the imagination, it is mechanically followed with stereotyped precision. An innovation in pattern, by copying some strange designs that strike the fancy, is far more likely. These distinctions in weaving may be conveniently divided into those that affect the knot, the warp, and the weft.[8]
The Knot.—Not only may a knot be tied as a Ghiordes or a Sehna knot, but it may have other distinguishing peculiarities; as, for instance, it may be of fine or coarse wool. This is most conveniently observed at the back, where it will be seen that the knots of rugs such as the Bokhara, Kirman, Joshaghan, and Bergamo are tied with fine yarn; while the knots of other rugs, as the Samarkand, Bijar, Gorevan, Kurdistan, Yuruk, and Kazak are tied with coarse yarn. Whether the yarn be fine, medium, or coarse, all specimens of any class will show a remarkable conformity. Also in some rugs the knots are drawn very tight against the warp, while in others the yarn encircles the warp loosely. Any one who has examined the back of many Sarouks, Kashans, Kirmans, or Daghestans, and rubbed the finger-nail against them, could not possibly mistake them for a Shiraz, Kulah, Yuruk, or Karabagh, which are less tightly woven. Again, as a result of using yarn in which the double thread that forms two or more ply has been very loosely or very tightly twisted together, there is some difference in the direction or slant of the strands forming the yarn, where it shows at the back, though this feature is not pronounced. For example, in most Afghans, Yuruks, Bijars, and others the strands of yarn where it crosses the warp in forming the knot lie for the most part in a direction parallel to the weft; while in other rugs, as Mosuls, Kurdistans, and Kazaks, the strands of yarn slant irregularly. Furthermore, in some rugs, as the Melez and Yuruks, as a result of the threads of yarn being strung rather far apart, each half of a knot encircling a thread of warp stands out at the back distinctly from the other with clear cut edges; while in many rugs, as the Shiraz or Sehna, each half is very closely pressed together. Also in some rugs, as Sarabends and Afshars, each of these half knots where they show at the back have the same length, measured in a direction parallel to the warp, as width, measured in a direction parallel to the weft; while in such rugs as the Kazaks, since the yarn generally consists of several ply, the length exceeds the width; and in a few rugs the length is less than the width.
The Warp.—The appearance of the back of a rug is partly due to the relative positions of the two threads of warp encircled by a knot. If, for instance, in any Kazak a pin be thrust through the nap wherever a single perpendicular line of one colour appears at the surface, it will be seen that each of the two threads of warp encircled by a single knot lie side by side with equal prominence. This is shown in Plate [B], Figs. 7 and 7a (Page 49), in which the former represents a section of a rug cut transversely to the threads of warp, and the latter the appearance of the rug at the back. The same will be found true of Beluchistans, Feraghans, Yuruks, and many others. If, however, a Kulah, Persian-Kurdish, or Karabagh be similarly examined, it will be seen that one thread of warp to each knot is depressed, so that the back has a slightly corrugated appearance (as in Plate [B], Figs. 8 and 8a). And in the case of a Bijar or Sarouk it will be seen that one thread of warp, included in every knot, has been doubled under so as to be entirely concealed from view; with the result that the foundation of warp has a double thickness, which makes the rug much stronger, as in Plate [B], Fig. 9, representing a Ghiordes knot, and Fig. 10 representing a Sehna knot. To be sure, it occasionally happens that in rugs of a particular class some may have each thread of warp included in a knot equally prominent and others may have one slightly depressed; or that in rugs of another class some may have one thread of warp depressed and others may have it entirely concealed; but as a rule these tribal features show a remarkable constancy. These relative positions of the two threads of warp encircled by a knot are partly due to the degree of closeness with which the threads of warp are strung, also partly to the method of inserting the threads of weft or “filling” between the rows of knots; but more than all else they are due to the way one end of the knots is pulled when they are tied.
The Weft.—In the character and arrangement of weft are technical differences that are more serviceable than any other feature for distinguishing between the rugs of different tribes and districts. So subtle are some of them that they can be learned only by long and painstaking study, and are appreciated by few except native weavers. Nevertheless, to any one who will carefully examine almost any well-known classes, it will be apparent that these differences in the weave are real, and that they are sufficiently constant to differentiate one class from another. The fine brown weft of the Bokhara, or equally fine bluish weft of a Sarouk that is almost concealed between firmly tied knots; the fine thread of cotton weft passing but once between two rows of knots and covered only by the transverse warp of the Sehna; the coarse thread of cotton weft similarly passing but once between two rows of knots in the Hamadan; the coarse thread of cotton weft that once crossing and recrossing appears irregularly between appressed rows of knots in Kermanshahs; the bead-like appearance of the threads of weft that, as a rule, pass many times between two rows of knots in Genghas; the crudely spun weft of coarse diameter crossing and recrossing once between the rows of knots in modern Mosuls; the very fine reddish brown weft that entirely conceals from view the warp in old Bergamos, —are features peculiar to these separate classes with which every rug expert is familiar. The weft of many other classes is equally distinctive, though there are exceptions to the types. It should be remembered, however, that the weave of many rugs woven over a hundred and fifty years ago is different from the weave of rugs woven only fifty years ago; and that many modern pieces cheaply made for commercial purposes are more crudely woven than were the same classes thirty years ago.