So instead of working in this way one should go at the whole matter very methodically. First of all, as soon as the object is in place and the easel and chair are in position, mark the location of the chair and the model stand on the floor in some way. A chalk mark around each leg of the easel and of the chair will do very well. Otherwise it is possible that some change will be made in their position and even the slightest shift is often enough to prove very confusing and cause inaccurate results. Then when you sit on the chair, sit right in the middle and keep erect. This is most important. For if you shift a bit to one side or the other or slump an inch or two, the object will present quite a different appearance (the change being particularly noticeable when one is drawing books and boxes and the like). So all the while that you are working hold the same position. As an aid to remaining stationary some instructors go so far as to have the student sight across some mark or point along the top of the object stand to some coinciding mark which can be made on the wall. Then the student, sighting from the first point to the second point, will establish his position and if he finds at any time that the points are not in line, one behind the other, he will know he is out of position. The same marks will prove useful to the instructor when he sits to give criticism, as they will enable him to view the objects from exactly the same point used by the student; in fact if he is of different height it may otherwise be very difficult for him to assume the correct position and unless he does so he cannot give the proper criticism.
As soon as the student has taken his position he should study the object for a few minutes before starting to draw. Notice the general shape of the mass, forgetting the detail but considering the simple form. Compare the height with the width. Is the mass taller than it is wide or is the opposite true? Is the general form square or round or oval or triangular? What are its most individual characteristics? Is it flat or rounded? Are its edges regular or irregular? Are the surfaces rough or smooth? When the subject has been analyzed with the greatest care the next step is to determine how large the drawing is to be and to locate the extreme limits of the object on the paper. If the subject is higher than its length it is best to place the paper in a vertical position so that the picture space will be in proportion to the object (or objects). Usually the size of the drawing will be less than that of the subject itself. Place a light mark towards the top of the paper to locate the extreme limit of the drawing in that direction, next another for the same purpose at the bottom, followed by others at the sides. These marks are shown at 1, 2, 3 and 4. Sketch 2, Figure 3. Next block out very lightly with a few sweeps of the pencil the larger proportions, the point barely touching the paper surface. Now set the drawing back near the objects. Compare. Is the height right in relation to the width? If it is hard for the student to determine this there is a test which may be applied here which is commonly used by artists, not only in object drawing, but in life drawing, nature sketching, etc., - namely, thumb measurement.
This test is known as thumb or pencil measurement. One eye is closed and the arm outstretched at full length towards the object, the hand grasping the sharpened end of a pencil held at right angles to the arm (more properly at right angles to the line of sight from the eye to the object). The pencil can then be used as a measure for comparing width and height or the length of one line with another (just as a ruler might be applied directly to the objects themselves), the thumb nail being allowed to slide along on the pencil until it marks any desired point. It is best to take the smaller dimension first and use it as a unit of measure for the larger. As the various proportions are compared in this way the corresponding dimensions on the drawing can be tested either by the eye or by laying the pencil directly upon them. If they are not relatively the same the differences will be obvious and corrections can be made. The value of this test is lost unless the pencil is kept at exactly the same distance from the eye, so the elbow must not be bent or the body turned; therefore, keep the shoulders firm against the chair back. At best this method of measurement is useful merely as a test as it is only approximately accurate, so the student should not employ it too frequently but should, instead, learn to depend on the eye, especially for the smaller proportions. If the drawing is frequently set back near the object he will soon learn to see and correct his own mistakes. In making corrections it is not always necessary to erase the incorrect lines, for if they are very light the new strokes can be made a bit heavier and will be easily distinguished. If the wrong lines prove confusing, however, erase them by all means.
Figure 4. Offering Some Suggestions on Composition, for Use in Object Drawing.
It is not enough to compare the height of the object with the width, or the relative lengths of different lines as is done by the thumb measurement, but the slant of the lines should be studied also, to make sure that they are pitched correctly. Hold the pencil at arm's length in such a position that it hides, or coincides with, some important line in the object, - then do the same with the same line on your drawing. Or hold the pencil vertically or horizontally and sight across it at some sloping line. Compare the angles formed by the various intersecting edges, too, and make corrections wherever necessary.