Book VI. Mechanick Power. 105
ſtands the line A B, as a Leaver of the firſt kind, whoſe propis D, the power in A, and the weight in B, to wit, in theend, or cuſp of the Wedge: In like manner let B C be ano-ther Leaver, whoſe prop is in E, the power in C, the weight
in B.
Notwithſtanding, his explication is altogether contrary to
the proportion of the Leaver; for by how much greater thediſtance is of the power from the prop, the greater is theforce of the power, in other like caſes; but in this caſe it is notſo, for if the Wedge be made ſhorter, and the power be inK L, and not in A, nevertheleſs the force of the Wedge willpe che ſamè: I ſay, the ſame of the leaver CB.Ahe ſecond᷑ is falſe, that: the Wedge touches the Body to bedivided with its point, or edge, becauſe, that for the moſtpart the extreams D and E only touch; neither when we mea-ſure the force of the Wedge, do we regard the proportionWhich is found between A D and D B, but how much theſnarper the Wedge is, or the leſſer angle it contains, the eaſierit divides.
Whence Ubaldus in his Mechanicks imagines, that if theWedge be recalled to a Leaver, tis to be explicated by adouble Leaver of the ſecond kind, whoſe common prop is inthe edge, or point B, the power in A and C, but the ſameinſtances occur as before; I add moreover, that a Wedge maywant a point, and nevertheleſs be as apt to divide as it wasbefore; ſo that the inclination of the planes remains theſame, touching in the points in which the body is to be cleft.
Fig. 87. Wherefore others recal the Wedge to an inclinedplane, a the body to be lifted up be A, under Which theWedge B is laid, that body being moved upon an inclinedplane, for tis all one, whether the body be drawn upon theplane, or the plane move under it, for to aſcend tis thoughtthe ſame; therefore there are in the Wedge two inclinedplanes. This conſideration is not abſurd, nevertheleſs, I con-tend that the whole difficulty remains, to wit, that the wholedoctrine of inclined planes is alike hard, labouring under theſame principle, wherefore
Iſay, The reaſon why the forces of che power are incre aſedby che Wedge, is, becauſe the power is moved much, andthe weight but little, or the greater motion of the power iscompared with che leſſer motion of the weight, and are joyn dtogether. P Wich