The Navajos have a singular kind of picture-writing which has been called “dry-painting.” These dry-paintings are made on the ground with dry sand of various colours.[57] All the designs are made with the utmost care and precision, being drawn according to an exact system, except in minor points, where the artist is left to his imagination. So far as known this system is not recorded in any way, but depends entirely on the memory of those in charge. Changes must therefore occur in the course of time. The sand is trailed out of the hand between the thumb and forefinger, and when a mistake is made it is corrected by renewing at that point the surface of the sand which forms the general ground for the work. No less than seventeen ceremonies are illustrated by drawings of this kind. Sand enters into some of the kiva ceremonies of the Moki, but in a different way. It is used more to maintain in position certain objects that belong to the ritual. [Illustration: SHELL DISC, TENNESSEE Diameter, 4.4 inches After Dr. Jones ] The mounds of the Mississippi valley have yielded antiquities of great interest, but thus far nothing that is beyond the ability of the ordinary Amerind to execute. Some shell discs, which Holmes suggests may have been time symbols, attract special attention. There are generally thirteen small outer circles on the discs, and thirteen is a number that occurs frequently in Amerind chronology. On other discs various objects are drawn, the one first to fix the attention of the white race being the figure of the cross because of its connection with the Christian religion. But it had no similar significance with the Christian cross. Crosses were found among almost all the tribes of North America, because a cross is an easy and a most natural figure to construct. Another emblem found throughout the world, and next to the cross the simplest figure to make, is that called the swastika, merely a cross 卐 with the arms broken at right angles. The Mormons firmly believe, along with Kingsborough, that the Amerinds are the Lost Tribes of Israel, and one of their elders has succeeded in translating some picture-writing thus: “_I, Mahanti, the 2nd king of the Lamanites in five valleys in the mountains, make this record in the twelve hundredth year since we came out of Jerusalem. And I have three sons gone to the south country to live by hunting antelope and deer._” Like the power to divine the future, the power to translate picture-writings is rare. In some of the Moundbuilder work there is a suggestion of a position for the makers intermediate between, say, the Algonquin and the Nahuatl or Aztec tribes. Their serpent symbols strongly resemble those of more southern tribes, and also some of the figures in shell and copper.