This section discusses the method of drawing horses using geometric principles, specifically with the use of compass and grids. It details dividing a square into nine parts and using these divisions to ensure proportional accuracy. The text provides specific instructions on how to place and proportion different parts of the horse, including the head.
THE FIFTH PART
I.
The method and practice of designing horses in profile using the compass and rules of geometry. We present here a demonstration of some reasons for the proportions of horses, showing the manner of designing them, using the compass and rules in proportion.
For example, to draw them in pairs, create a square divided into nine parts labeled A. B. C. D. E. F. G. H. I. L. M. N. O. P. Here, set the endpoint at the head, and the numbers show the proportions as noted, and these are as shown in your figure. Position the head, and apply the spaces accurately with M. B. Make space B. S. my foot, Y, S. T. one foot for the quadrant, to enter by the mare head straightforwardly, I say.
Establish the BDIBHG to validate this line atop well arranged with three inviting placements and allow the horses in good order plan thus, follow this. a. g. through four lines measured accordingly.
Let the will be processed of you to measure up with fifth illustrated in principle by accurate reflection as usual.
Translation Notes
"Quadrate" refers to dividing the area into a grid to aid in proportions, which might be a foreign concept in modern drawing as it was used for scaling and proportion in classic terms. "Mare head straightforwardly" is likely referring to a method for correctly aligning parts of the body in drawing.