7 



cumscribing cube, made in cardboard, and painted 

 according to their simple forms. 



1876. Exhibited by Rev. Nicholas Brady, M.A. 



The collection consists of simple forms and common combina- 

 tions, so graduated as to show the passage of one simple form 

 into another, the intermediate forms being combinations of the 

 two in different proportions. 



Throughout the whole series the cube is coloured in red, the 

 octahedron in blue, the rhombic dodecahedron in green. The three 

 faced octahedron is yellow, the four faced cube is purple, the 

 icositetrahedron is brown. 



The two derivative forms produced from any of these by the 

 same kind of hemihedrism are coloured in light and dark shades 

 of the same colour. Thus the two tetrahedra are coloured light 

 and dark blue, the positive by the lighter tint. The three-faced 

 tetrahedra are yellow and orange. The pentagonal dodecahedra 

 are light and dark purple and the two triakistetrahedra light 

 and dark brown. 



Of these models 



12 show the cube modified by an octahedron, the two com- 

 ponent tetrahedra being indicated by the tint. 



12 show the cube modified by the rhombic dodecahedron, with 

 or without the octahedron. 



6 show the cube modified by the four-faced cube and also a 

 gradation from one simple form to the other. 



10 show the cube combined with positive and negative penta- 

 gonal dodecahedra. 



5 show the cube combined with the icositetrahedron. 



6 show the cube combined with the positive and negative 



triak is-tetrahedra. 



6 show the cube combined with the 3 -faced octahedron. 



10 show the cube combined with the positive and negative 

 3 -faced tetrahedra. 



24 show the octahedron and its derived tetrahedra in com- 

 bination with each other, and with the rhombic dodeca- 

 hedron. 



18 show the octahedron or tetrahedron combined with the 

 icositetrahedron or its hemihedral forms. 



6 show the octahedron or tetrahedron combined with the 

 3 -faced octahedron. 



20 show the octahedron or tetrahedron combined with the 

 hemihedral forms .of the 3-faced octahedron and icosi- 

 tetrahedron. 



15 show the rhombic dodecahedron with the 4-faced cube,, 

 and its derived pentagonal dodecahedra. 



22 show the rhombic dodecahedron with the positive and nega- 

 tive 3-faced tetrahedra. 



3 show the rhombic dodecahedron with the icositetrahedron^ 



