You should also be holding the stick at a 90° angle to your line of vision. When measuring, shut one eye and use your other eye to view the object, maintaining the same viewpoint until all measurements are completed.
Look across the stick and line up its top end with one edge of the object. Then adjust the tip of your thumb on the stick so that it lines up with the bottom edge of the object (Figure 8A). The space between the top edge of the stick and the tip of your thumb comprises the height of the object. Now, without moving your thumb, rotate your hand and position the tip of your thumb at a side edge of the object.
This will give you an idea of how the object’s width compares to its height. The width of the object is a little more than three-fourths of its height. These measurements let you know how much space the object will occupy in your drawing.
On a clean sheet of paper from your sketch pad, determine where you want the base of the object to appear. You can refer to the placement of your thumb on the measuring stick to get an idea of how much space you’ll need.
Once you’ve decided on the location of your baseline, mark the location in pencil on your paper. Then place a mark on your paper to indicate where the top of the object is concerning its baseline. Now, without moving your thumb from the stick, rotate your hand and align your thumb with a side edge of the object again.
Look at the stick and make a mental note of the object’s width concerning its height. On your paper, mark the width of the object in pencil.
Use the measuring stick in the same way to measure other details of the object. Always compare new measurements with those you’ve taken previously. This will help you to maintain accurate proportions in your drawing.
As mentioned earlier, you can also use the measuring stick to help you determine the position of objects concerning one another. First, align the stick with one edge of your first object; then, following the length of the stick with your eye, note where the extension of that edge intersects the other object
You can also use the stick as a horizontal level and a vertical plumb. A horizontal level is any device that helps you determine a straight horizontal line. Similarly, a vertical plumb allows you to determine a straight vertical line. As a level, the stick becomes a horizontal reference. Using it, you can determine to what degree the edges of an object angle away from the horizontal plane.
The same angle you see between the edge of the object and the levelled stick should appear in your drawing. This angle belongs between the drawn line representing the object’s edge and a reference line drawn parallel to the top and bottom of your paper
To use the measuring stick as a plumb, hold the stick lightly at the top and let it hang vertically by its weight. Look along the vertical edge of the stick and check the positions of your object’s vertical edges concerning the stick.
You can also determine how much an edge tilts away from the vertical reference. Compare your model to your pencil sketch and lightly draw a vertical reference line on your paper