The (ecotid Claffis contains fix differences of 
she Baps of a Plane. In the Hsh gthf toth, and 
11th figures, there are only fix fides 5 yet with 
ehis difference,that in the 8th figure all the fides 
are equal in the ^th and nth, not all but only 
the oppofite fides are equal; but in the lothj all 
oppofic fides arc unequal. In the i zth figure,the 
Plane oi the hafe, which Ihouid be hexagonal® 
contains twelve fides. The 13?^ figure lhews> 
how, by laying a new Chryftallin matter upon 
the planes of the Pyramids,fomtimes the length 
of the fides, and the number alfo are varioufly 
changed in the plane of the bafe,without chan-* 
ging the angles. 
The fix following figures do explain two di¬ 
vers kinds of Angular bodies ofThe i4th, 
^th and i6th figures ferve to explain thofe An¬ 
gular bodies of Iron,that have twelve planes; & 
of them the 14?^ figure reprefents all thofe 12 
planes laid out in one plane,fix of which are tri¬ 
angular and polilh’c; the other fix, pentagonal 
and ftreaked.The i^th figure is the plane of the 
hafe of the fame body. The figure is the 
plane of the axis of the fame body. 
The 17th, 1 8th and 19th figure ferve to ex¬ 
plain thofe Angular bodies of Iron, that have 
thirty planes 5 and of them the lyth figure exhi¬ 
bits all thofe 30 planesjcxplicated in one plane j 
Jix of which are pentagonal and polifh*f5 twelve 
are triangulatipolifli’t likewife,- fitxare triangu¬ 
lar and ffreakedjand fix are quadrilateral oblong 
and poliih’t-The figure is the plane of the 
hafe of the fame body. The 19?^ is the plane of 
the axe pf the fame body. 
