Plates IX to XV, inclusive, are to be drawn by the student for practice in applying the principles of orthographic projection, intersections and developments, isometric and oblique projection, and for practice in lettering. These plates are to be made 11 inches by 15 inches outside, with a margin of 1/2 inch, making the clear space for the drawing 10 inches by 14 inches. All the plates are to be inked.

## Plate IX

After laying out the border line on the plate, draw a ground line horizontally across the upper part of the plate, 3 inches below the upper border line. On this ground line six figures, spaced as regularly as possible, are to be drawn, as follows:

1. Draw the projections of a line 1 1/2 inches long which is parallel to both planes, 1 inch above the horizontal, and 3/4 inch from the vertical.

2. Draw the plan and elevation of a line 1 1/2 inches long which is perpendicular to the horizontal plane and 1 inch from the vertical. Lower end of line is 1/2 inch above H.

3. Draw the projections of two intersecting lines: one 2 inches long to be parallel to both planes, 1 inch above H, and 3/4 inch from the vertical; and the other to be oblique to both planes and of any desired length.

### Note

The idea for drawing the three figures referred to in 1,2, and 3 can be obtained from Figs. 104 and 105 in this textbook.

4. Find the true length of a line whose vertical projection is 1 1/4 inches long, the left end on the ground line and inclined at 30 degrees. The horizontal projection has the left end 1/2 inch from V, and the right 1 1/2 inches from V.

5. Find the true length of a line whose horizontal projection is 1 inch long, whose right end is 1/2 inch above the ground line, and inclined at 60 degrees. The vertical projection has the right end 1/2 inch below the ground line and the left 1 inch.

6. Find the true length of a line whose projections are perpendicular to the ground line. The horizontal projection is 2 inches long, the bottom end being 1/2 inch above the ground line. The vertical projection is 1 inch long, the top end being 1/2 inch below the ground line.

### Note

The idea for drawing the figures referred to in 4, 5, and 6 can be obtained from Figs. 120 and 121 in this textbook.

In the lower half of the plate, four more figures are to be drawn, also spaced as regularly as possible, so that the finished plate will be well balanced:

7. Draw the plan and elevation of a round bolt with a square head. The head is to be uppermost in the elevation. The bolt is to be 2 inches long and 1/2 inch in diameter. The head is to be 3/4 inch square, 1/4 inch thick, and have one face parallel to V.

8. Draw the plan and elevation of a round bolt having the same dimensions as in 7, but with a hexagonal head; the head to be uppermost in the elevation, and to be ) inch in width between faces 1/4 inch thick, and to have one face parallel to V.

9. Draw the plan and elevation of a cylinder, perpendicular to H, 2 inches high and 2 inches in diameter, with a hole 1 inch in diameter passing vertically completely through it.

10. Draw the plan, elevation, and end view of a rectangular block 6 inches long, 2 inches wide, and 1 inch thick. One of the 2 inch by 6 inch sides is to be parallel to H. The right end is turned down to a cylindrical form 1 inch in length and 1 inch in diameter.

In all the work of this plate construction, lines should be fine dotted lines and should be inked in.