Most of the existing khipu are from the Inka period, approx 1400 – 1532 CE. The Inka empire stretched from Ecuador through central Chile, with its heart in Cuzco, a city in the high Andes of southern Peru. Colonial documents indicate that khipu were used for record keeping and sending messages by runner throughout the empire. There are approximately 1000 khipu surviving in museums and private collections around the world.
A khipu with principal parts labeled. Photo Courtesy of Peabody Museum, Harvard University
The word khipu comes from the Quechua word for “knot" and denotes both singular and plural. Khipu are textile artifacts composed of cords of cotton or occasionally camelid fiber. The cords are arranged such that there is one main cord, called
a primary cord, from which many pendant cords hang. There may be additional cords attached to a pendant cord; these are termed subsidiaries. Some khipu have up to 10 or 12 levels of subsidiaries. Khipu are often displayed with the primary
cord stretched horizontally, so that the pendants appear to form a curtain of parallel cords, or with the primary cord in a curve, so that the pendants radiate out from their points of attachment. When khipu were in use, they were transported
and stored with the primary cord rolled into a spiral. In this configuration khipu have been compared to string mops.
Each khipu cord may have one or many knots. Leland Locke (see references) was the first to show that the knots had numerical significance. The Inkas used a decimal system of counting. Numbers of varying magnitude could be indicated by knot type and the position of the knot on its cord. Beginning in the 1970’s, Marcia and Robert Ascher conducted invaluable research into the numeric significance of khipu, and developed a system of recording khipu details which is still in wide use today among khipu researchers. More recently, researchers such as Gary Urton have recognized the depth of information contained in non-numeric, structural elements of khipu.
The primary cord is an essential component of any khipu; it is the element to which all other features are attached. Most primary cords are spun and plied, though there are examples of primary cords which are braided or wrapped. Typically
the primary cord is thicker than its pendants. Prinary cords range in length from 10 cm to 514 cm. When complete, primary cords often have one doubled end (the result of folding a group of cord components in half during the plying process)
and one end with a knot. They may also have both ends knotted or ravelled, or may include needlework bundles or other special attachments.
Pendant cords hang from the primary cord. Pendants may be spaced closely together or far apart. Often the pendants are arranged in clear groups. The groups may be separated by a space, or may be marked by a change in color of the pendant cords. Any pendant may have additional cords hanging from it; such cord are termed subsidiaries. Pendants which leave the primary cord in a direction opposite to most other pendants are called top cords. Some pendants have both of their ends attached to the primary cord; these are called loop pendants.
Section of the Calendar Khipu showing loop pendants and top loop pendant. Image courtesy of Centro Mallqui, Leymebamba, Peru. (Photo by Gary Urton)
Most surviving khipu are made of cotton. Cotton was grown in several natural colors, including white, light brown, medium brown, and green. All of these colors were used, and some khipu use dyed fiber to expand the range of hues. Cotton khipu may include cords made from the fleece of llama or alpaca, termed camelid fiber. There are also a few khipu made entirely of camelid
Spinning and Plying
The fundamental component of a khipu cord is made by taking fiber and twisting it to form a thread. In the finished thread, the fibers form an angle with the vertical axis of the thread. This is the angle of twist. The twist may be inserted in one of two directions. When the fibers angle from upper left to lower right, like the cross-stroke in the letter S, it is termed S twist; when they angle from lower left to upper right it is termed Z twist, because the angle is like the cross-stroke in the letter Z
A certain amount of twist is needed to hold the fibers together. Twist over that amount resides in the thread in the form of energy. A freshly spun singles thread almost always has extra energy, which makes the yarn want to kink back on itself and form snarls. One way to counteract this is to ply two yarns with the same twist together in the direction opposite that in which they were originally spun. That is, two S-yarns would be spun together in the Z direction; this operation is called plying, and each S-yarn is called a ply. The Z-twist of the plying operation holds the two yarns together and balances out the S-twist in the singles so that the finished yarn is stable and has no tendency to kink or snarl.
Many khipu cords are a solid color, but khipu makers were ingenious in combining colors during spinning and plying to create multi-colored cords. The most common uses of color in cord construction are described here.
When two solid-colored components of different colors are plied together, the resulting cord has angled stripes like a peppermint stick. These cords are usually referred to as barber-pole cords.
Mottled cords are clearly made up of two (or more) colors, but rather than the clear striping of barber-pole cords, the colors appear in randomly mixed bits and pieces. This color arrangement can be achieved by spinning singles with two colors held together, mixing the colors in the single plies, or by randomly mixing singles of different solid colors. For instance, a 12-component mottled cord could be made up of three white singles plied with three brown singles into 6-ply cord, then doubled and re-plied to make a 12-component cord.
Some cords change color along their length. In the photo above, cords change from blue to white. This is accomplished in the spinning, it is not a result of dyeing or painting the finished cord. One way to create such a join is to take the blue plies and double them around the midpoint of the white plies, pulling the white and blue thread in opposite directions. The blue and white will be joined with interlocking loops, and when the plying is complete, the color appears to change abruptly in the middle of a cord.
The two different faces of pendant cord attachment. Illustration by Julia Meyerson.
Pendants are attached to their primary cord by opening up the doubled end of the cord to form a loop and passing the length of the pendant around the primary cord and through the loop. This creates a half-hitch which is quite snug, due to the plying energy in the cord. The half-hitch has two different faces, termed recto and verso and shown above.
Khipu knots occur in one of three types: single knots, long knots, or figure-eight knots. A single knot is a simple overhand knot. To make a long knot, the cord is wrapped around itself two or more times, creating a cylindrical knot with a diagonal axis. In a figure-8 knot, also called an E-knot, the cord forms the shape of the numeral 8, with the ends exiting through the holes in the 8. Each knot can be made in two different orientations, resulting in a different slant to the axis of the knot. Like the different spinning and plying directions, the knot orientations are termed S and Z.
In numeric khipu, the type of knots and their position indicate numeric value. Single knots may occur alone or in clusters. Each single knot stands for 10, 100, 1000, or greater powers of 10. The larger powers are positions closer to the primary cord. Mulitple single knots in a cluster indicate multiples of the designated power of ten; for instance, a group of 3 single knots in the hundreds position would mean 300. Unit values are denoted by long knots or E-knots; ordinarily a string will have a long knot or an E-knot but not both. An E-knot indicates the value 1. Long knots are valued according to their number of turns: 2 - 9.
Photo by Gary Urton.
Khipu showing bands of knots, indicating different numerical values. American Museum of Natural History, 41.2-6994. Photo by Gary Urton.