. 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. , tothe child unknown, may be brought into his mental horizon. If we work upward and outward in this manner, the final andgrander concept of the world itself—as a great valley with its Intermediate Molding in Sand. 35 ocean river, the Atlantic—comes upon the mind, to unify not onlythe geography, but the history of the world (Fig. 14). Rivers are the most important aqueous agents in modifyingthe surface of the
. 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. , tothe child unknown, may be brought into his mental horizon. If we work upward and outward in this manner, the final andgrander concept of the world itself—as a great valley with its Intermediate Molding in Sand. 35 ocean river, the Atlantic—comes upon the mind, to unify not onlythe geography, but the history of the world (Fig. 14). Rivers are the most important aqueous agents in modifyingthe surface of the earth. Springs, as they issue into open day,naturally seek a lower level; and numbers of them meeting inone channel form streams, which again join in some lower valleyand produce rivers of various sizes. Rivers thus form a speciesof natural drains by which the excess of moisture that falls uponthe land is returned to the sea. They are of all dimensions; inbreadth from a few feet to many miles; so shallow that a boycould wade them, or so deep as to float the largest ships. Inlength of course, they range from forty miles to as many hundredmiles. 36 Intermediate Molding in Fig. 15. ILtuuon X. Volcanoes.—I. ** What goes into the head through the eyes never comes out again.—GermanProverb. An Active Volcano. Procure some molders clay, and dampen it until it will packwhen pressed in the hand. Sand or common red clay will dovery well in place of the other, but molders clay is cleaner. Pul-verize an ounce of chlorate of potash, and then mix it thoroughlywith half an ounce of dry white sugar. Procure a small quantityof sulphuric acid (H^SO^). Now build up a small pile of the clay, and scoop out from thecentre a part, as in this figure. (Fig. 15.) Put a piece of paper, about four inches in diameter, in thebottom of this hole ; then put in the mixed potash and sugar. Take a pencil or pen-holder (Fig. 16), and run it through acircle of paper about as large as the first one ;
Size: 2401px × 1041px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookidmapmodelingi, bookyear1894
