If the sheet bearing the design or matter to be copied may be marred without objection it is ruled lightly into pencil squares of equal size. Corresponding squares of the same size, larger, or smaller, according to the size of the new drawing, are then ruled on the drawing paper, and the work is sketched square by square. If the original sheet may not be marred the same result can be obtained by drawing the lines on a transparent oversheet. This method is serviceable for enlarging or reducing simple work that includes no great amount of detail; if great precision of detail is required the original should be enlarged or reduced by photography or by the pantograph. THE "SHADOWLESS DRAFTING TABLE." One of the most useful contrivances that has been made for tracing a drawing on the same scale is called by its manufacturers the "shadowless drafting table." The essential features of this table are a wooden box inclosing strong incandescent lights and bearing a ground-glass top. A drawing placed on the ground glass can be so illuminated as to make its lines conspicuous and readily traceable even through relatively thick paper. The table is particularly useful for tracing sheets upon, which the lines are indistinct and would not be discernible under tracing paper with reflected light. It is also useful in preparing drawings in which certain features must register perfectly over each other. In fact any drawing that does not require enlarging or reducing can be traced with great facility by the use of this drafting table, and it is particularly useful for tracing faint lines on old and poorly preserved prints or drawings. Such a table has been installed in the section of illustrations, where it can be used by authors and others. TOPOGRAPHIC FEATURES. RELIEF. The effect of relief is expressed on a map by three methods--by contours, by hachures, and by shading. (See fig. 6.) The first method does not give pronounced pictorial expression of relief, though it gives correct shape and exact elevation; the others are mow pictorial, but they do not give exact elevation.