The title of the book is more or less telling. It is easy to understand that the author is trying to transmit his knowledge about perspectives and the drawing of them.
The complete title is: “La Perspective, avec la raison des ombres et miroirs”, in English: “Perspective, with the reason of shadows and mirrors”. Perhaps there were several works of the same kind which explains this precision.
We were not able to have the book in our own hands but by searching for information on the Internet, we discovered that it was only about a hundred pages long. We can therefore deduce that this book is a kind of popularization of the author’s knowledge. It was certainly intended for an amateur or even a beginner audience.
When we open the book, we discover that it is divided into a certain number of chapters, each of which bears the name of an object or a group of objects. These vary enormously, from the very simple (square, circle, cube, cross) to the sometimes complex architectural concepts (pillars, stairs, room, fortress). In each chapter, the author teaches us how to draw these objects in perspective. About a double page is enough for Salomon de Caus to explain the basics of the theory of his art. Generally, there is a one-page text accompanied by an illustration, presumably drawn by the author, which shows the technique applied to the letter.
Salomon de Caus is an engineer and architect. His work is therefore the work of a professional. One can therefore expect to find verified information at the cutting edge of the knowledge of the time.