Hide Article Text (OCR)
the different Cryjlalllne Forms* 409the figures I fhall not enlarge on it, as it may be eafily deduced from what we have adopted in regard to quadrangular prifms. But, it fometimes happens that three of the folid angles, taken alternately, are replaced by facets, while the intermediary angles remain untouched. In that cafe the ex-prdiion of the prifm will be that feen fig/ 24. '34. The rhomboidal dodecaedron, in certain fpecies, as that of red filver ore, has fix of its faces which perform the functions of the planes of a prifm ; while the fix other faces enter into the analogy of rhomboids {29) 3 /o that the faces of each order may undergo particular decrements, independently of thofe which regard the faces of the other order. Figure© o2$ reprefents the expreffion of this dodecaedron. Each face of the fummit, in the fame cafe, may be confidered as the bafe of an oblique quadrilateral prifm (20), and the adjacent planes as belonging to the fame prifm. Thus the manner of placing the letters which indicate the decrements, and the figures that accompany thefe letters, will be analogous to that which takes place in quadrilateral prifms.
Newspaper Details
Philosophical Magazine
London, Middlesex, GB
Tue, Jan 01, 1799
Page 101
Full Page
Clipped by
Anonymous
USA 15 Jul 2024
Other Publications Near London, Middlesex
Bingleys Journal
Arminian Magazine
London Daily Mail
London Stars and Stripes
London Daily Universal Register
