. Map modeling in geography : including the use of sand, clay putty, paper pulp, plaster of Paris, and other materials : also chalk modeling in its adaptation to purposes of illustration. Fig. II. The Spring. 1. The child is allowed to pour some water upon sand, and tofind that the moisture soon passes through it. The water sinks through the sand freely. There are emptyspaces between the little grains of sand, and the water readilypasses among such spaces. Sand is loose and porous [pervious], and may become like akind of sponge, filled with the water from the surface of theground. 2. Let the c
. Map modeling in geography : including the use of sand, clay putty, paper pulp, plaster of Paris, and other materials : also chalk modeling in its adaptation to purposes of illustration. Fig. II. The Spring. 1. The child is allowed to pour some water upon sand, and tofind that the moisture soon passes through it. The water sinks through the sand freely. There are emptyspaces between the little grains of sand, and the water readilypasses among such spaces. Sand is loose and porous [pervious], and may become like akind of sponge, filled with the water from the surface of theground. 2. Let the children pour some water upon a quantity of clay,and find that the tough clay does not allow the water to passthrough. The little particles of clay fit close to each cannot pass through the mass of is impervious. Many rocks are porous, and are also cracked or may pass down through the beds of many close-grained Primary Molding in Sand. 29 rocks, such as limestone or sandstone, because there are many-joints or cracks. 3. The children are allowed to build up a hill of clay, and Q!s^^^^. -^.^^\VWh Fig. 12. make its slopes quite smooth. Then they may cover it with alayer of mixed sand and gravel. 4. At the base of the hill, scoop out a part of the sand downto the layer of clay. Pour the water on the slope at the top, andafter a few hours some will be found collected in the little hollowat the base. 5. Where does the rain go ? Some of the rain soaks down into the ground and finds its waythrough the loose soil and sand, or even between the crevices inthe harder rocks, down to the layers of clay. Here it will followthe line until it comes to some outlet at the lower surface, andthen gushes out as a spring. When this water does not appear at the surface, we may digholes called wells, and catch the water. 30 Primary Molding in Sand. A Brook Basin. The relief form of the school district should be studiedthrough actual observation. Land surfaces consist o
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Keywords: ., bookcentury1800, bookdecade1890, bookidmapmodelingi, bookyear1894
