16 CUBIC SYSTEM. In the form 211, d — 48 ° n ' In the form 311, d — 35 o 6. F = 33° 33'. F = 60° 29'. 54. In the form Mclc (fig. 22), + k 1 F~+~iF’ b? — 2 ¥ FIG. 22. COST = COST = A 2 + 2k 2 ' In the form 1-211, f = 33 0 33', T = 70° 32'. In the form *311, f = 50° 29', T = 50 o ^ 5o. In a combination of the forms ino 7, /.7, 11 - hkk, forming the solid angle in which the’tX. ^ 8 ° f appear upon each of the angles of 100 ^ edgeS F meet > 211.100 = 35° 16', 211,010 = 65° 54', 211,001 311.100 = 25° 14', 311,010 = 72° 27', 311,001 : In a combination of the forms 100 A;u *u r latter, forming the solid angle in which theVrX®! th ° appear upon each alternate angle of 100 gCS F meet > In a combination of the forms m m * truncate the eolid angle, „f m in m 211,111 = 19° 28'. 311,111 i 65° 64'. 72° 27'. 29° 30. FIG. 23. COSD COSG 2V _ ¥ + ¥’ h? -f- 2 hh 2W~-f ~¥' 122, D = O 00 CO 57', 133, D = 26° 32', 233, D = 60° 29',
