In which is explained the correspondence that natural mobiles have with the weights of a balance.</s>
</p>
<p>
<s id="id.1.1.6.01.00"/>
<s id="id.1.1.6.01.01">Thus we will first examine the things that happen in the scale pan, so that we may then show that all these things happen in the case of natural mobiles.</s>
</p>
<p>
<s id="id.1.1.6.02.00.fig"/>
<s id="id.1.1.6.02.01"> Thus let line ab be understood to be an equal-armed balance, whose center, above which motion takes place, is c, precisely dividing line ab in two; and let two weights, e and o, be suspended from points a and b. </s>
<s id="id.1.1.6.02.02">Accordingly in the case of weight e three things can happen: either it is at rest, or it is moved upward, or it is moved downward. </s>
<s id="id.1.1.6.02.03">Consequently if weight e is heavier </s>