E. 8. Dana—Chondrodite from the Tilly-Foster Iron Mine. 91 
the a angles. Calculated from these angles the 
parameters 
a Sait cea yab6 . tao) < bi Oeeeu. 
and the angle for the fundamental prism is 
IA T(110 A 110)=58° 15! 46” or 94° 44’ 14”, 
TasiE I. 
Chondrodite. Humite. 
og + (018) A=0 (001) A (v. Rath) 
| K Calcul Measured, | Calculated | Gaiculated. 
¢ | 14/011 )147° 32’ 39"| 122° 44" (ap,)}122° 27% 21°/122° 27° 49" 
a 
et) 54/205 | 90 *149 55 48 1149 58 48 
2 
él x7 | 203) 90 135 59 136 1 17 4135 62 15 
é| 2.%/ 201) 90 109 4 109 3 24/108 57 650 
Tt2 
| 772 | 247/129 42 9 |#135 18 50/135 18 50/135 17% 40 
4° 
| g-2 | 245/137 25 45 | 125 52 125 50 6/125 49 0 
eos ee 
re)5 2) 243/146 27 42] 113 254 (113 25 36/113 24 45 
m)4-2 19411154 9 9| 98 14 98 13 6/98 12 47 
Ape Ste 
im) 6-5 | 641|125 43 56| 95 22 95 19 40/95 17 59 
ef. 
m} 5 [223/127 1 31 125 3 49/125 2 47 
jm] 2 [221/136 45 24] 103 11 103 10 4/103 9 35 
The “ptteeeng table* (I) includes the 1 angl - 
principal angles meas 
ured on the e crystal, and also those cal Ieulated from the 
above | patetisetorss ; mm addition, the corresponding angles for 
The anal type IT, are also given, as ene ite by vom Rath. 
+h te bis ie Soansusies the form used in Dana’s “ Mineralogy ”) and 
also of hy ee Se omitted here, as the 
relations of with sufficien' on the spherical pro- 
