388 



Professor Sir James Dewar 



[Jan. 18, 



One interesting variation of this study was made by employing 

 a frame composed of two thin platinum wire squares, linked by 

 cellulose fibres vertically between the corners to form a cube, and 

 supported by a pyramidal frame formed by four equal fibres from 

 the upper cube corners joined together at the supporting apex. A 

 similar pyramidal frame inverted was also formed below, the four 

 fibres in this case being attached to a small lead weight. The result- 

 ing formation when the framework was dipped in soap solution is 

 represented geometrically in the following three views, two eleva- 

 tions {a) and (J)) and a plan {c) (Fig. 27). 



This is really a combination of the cube and the octahedron 

 patterns (already described) obtained by equally dividing the octa- 

 hedron horizontally, and adding the separated portions to the top 

 and bottom of the cube. The central square plane of the simple 

 cube is thereby pulled out to an irregular iiexagon achh'c'a' by the 

 kite-shaped planes dc e, 0' d' c e\ of the divided octahedron, with 

 a consequent rearrangement of all the films at equal inclinations. 



