Fig. 34
A Diagram from the Annals of Botany, 1912, Vol. 26.
In certain cases it is possible to combine detail and diagram in one drawing; this is shewn in Fig. 32, taken from Dr. Ridewood's admirably illustrated memoir on the Gills of Lamellibranchiata (Transactions of the Royal Society of London, B. vol. 195, 1903). The shading employed was either done by the draughtsman (at ch and in the cells with irregularly arranged dots), or else was put on the block during its manufacture (af). If a lens be used, the difference will at once be obvious.
The finished drawing should be bold and neat, and all lettering should be very clear. If several figures are included in one diagram they may be separated one from the other by ruled lines, and in no case should one tier of figures—taking the frames as the boundaries—unevenly overlap another tier, otherwise the diagram, to use an expressive phrase, will look "like a pig with one ear."
Under the heading of diagrams must be included the representation of apparatus. There are two ways of drawing apparatus; the objects may be drawn as a study in still life, as, for example, in many of the figures illustrating Deschanel's Natural Philosophy (London, 1890) or they may be represented in a purely conventional fashion. The latter is the better way, and it is preferable to draw for the most part in section in order that all connections, inlets, outlets, etc., may be clearly shewn.
A study of a good example is infinitely better than a written description, wherefore Figure 35 has been inserted.
