TO THE COURTEOUS

AND CANDID READERS.

A decorative woodcut ornament consists of four stylized fleur-de-lis motifs in a horizontal row.

A historiated woodcut initial "L" depicts a landscape scene with architectural elements, including a bridge and buildings, framed in a decorative border.

Machines in all centuries have brought the greatest convenience to human operations, overcoming with ingenuity those necessities encountered in both civil and military constructions, leaving aside for now self-moving machines and others that provide utility and curiosity. These present figures have come into my hands, concerning operations of both water and animal power, as well as spiritual referring to pneumatic or wind-driven mechanisms, and declared by me. Within them are all those principles that Aristotle treats and proposes in his Mechanics, with the foundation of which man can serve himself at any time to invent machines according to the needs that may present themselves to him. No one should be discouraged while putting any of these machines into operation if the desired operation does not succeed for them; because one must take note of the progression of the power of the motors and of weights in their variations, with respect to the accidents which, with air, with water, and in other manners, change almost their nature. Hence it is that sometimes in small form, almost miracles are performed, while in large form, one sometimes loses the knack. And therefore one is not to be amazed, because the defect does not proceed from the Mechanics, nor from their principles, but only from the operator, perhaps not well educated, or who has not understood, discussed, and communicated with persons of the profession. I will not dispute for now whether, by means of machines, time, fatigue, or expense is saved; but I do say that with ingenuity one