into four parts of which two are pyramids equal and like to one another and the other two are equal prisms greater than half the whole pyramid. Prop. IV. If two pyramids of equal altitudes having triangles as their bases be each divided into two pyramids and two prismas as in the preceding proposition, then the ratio of their bases shall be equal to that of the prisms. Prop. IX. A cone ( शत्रु ) is a third part of a cylindex (समतलमस्तकपरिधि) having the selfsame base (a) and altitude मस्तकपरिधि) with it. Prop. XIV. Two concentric spheres being given, it is required to inscribe in the greater sphere a solid figure of many sides (i. e. a poly- hedron), the superficies of which shall not touch the less sphere and if a similar polyhedron be inscribed in another sphere, these two polyhedrons shall be in treble ratio of that in which the diameters of the spheres are. BOOK XIII. Prop. II. No enunciation is given for this Prop. and it simply seems to be an alternative proof of the 1st Prop. Prop. IV. For this also no enunciation is given and the Prop. seems to be an alternative proof of Prop. III.
