The ancient Peruvians had no manuscript characters for single sounds; but they had a method by which they composed words and incorporated ideas. This method consisted in the dexterous intertwining of knots on strings, so as to render them auxiliaries to the memory. The instrument consisting of these strings and knots was called the QUIPU. It was composed of one thick head or top string, to which, at certain distances, thinner ones were fastened. The top string was much thicker than these pendent strings, and consisted of two doubly twisted threads, over which two single threads were wound. The branches, if I may apply the term to these pendent strings, were fastened to the top ones by a single loop; the knots were made in the pendent strings, and were either single or manifold. The length of the strings used in making the quipu were various. The transverse or top string often measures several yards, and sometimes only a foot long; the branches are seldom more than two feet long, and in general they are much shorter. The strings were often of different colors; each having its own particular signification. The color for soldiers was red; for gold, yellow; for silver, white; for corn, green, &c. This writing by knots was especially employed for numerical and statistical tables; each single knot representing ten; each double knot stood for one hundred; each triple knot for one thousand, &c.; two single knots standing together made twenty; and two double knots, two hundred. This method of calculation is still practiced by the shepherds of the Puna. They explained it to me, and I could, with very little trouble, construe their quipus. On the first branch or string they usually place the numbers of the bulls; on the second, that of the cows; the latter being classed into those which were milked, and those which were not milked; on the next string were numbered the calves, according to their ages and sizes. Then came the sheep, in several subdivisions. Next followed the number of foxes killed, the quantity of salt consumed, and, finally, the cattle that had been slaughtered. Other quipus showed the produce of the herds in milk, cheese, wool, &c. Each list was distinguished by a particular color, or by some peculiarity in the twisting of the string.