<p> <s id="g0100002">English translation by Walter Stanley Hett, M.A.</s> </p>

</section> </front> <body> <chap> <p> <s id="g0110101">Remarkable things occur in accordance with nature, the cause of which is unknown, and others occur contrary to nature, which are produced by skill for the benefit of mankind.</s> <s id="g0110102">For in many cases nature produces effects against our advantage;</s> <s id="g0110103">for nature always acts consistently and simply, but our advantage changes in many ways.</s> <s id="g0110201">When, then, we have to produce an effect contrary to nature, we are at a loss, because of the difficulty, and require skill. </s><s id="g0110201a">Therefore we call that part of skill which assists such difficulties, a device.</s> <s id="g0110202">For as the poet Antiphon wrote, this is true: &quot;We by skill gain mastery over things in which we are con&que;red by nature.&quot;</s> <s id="g0110203">Of this kind are those in which the less master the greater, and things possessing little weight move heavy weights, and all similar devices which we term mechanical problems.</s> <s id="g0110301">These are not altogether identical with physical problems, nor are they entirely separate from them, but they have a share in both mathematical and physical speculations, for the method is demonstrated by mathematics, but the practical application belongs to physics.</s> </p>

<p> <s id="g0120101">Among the problems included in this class are included those concerned with the lever.</s> <s id="g0120102">For it is strange that a great weight can be moved by a small force, and that, too, when a greater weight is involved. For the very same weight, which a man cannot move without a lever, he quickly moves by applying the weight of the lever.</s> </p>