CRYSTALLOGRAPHICAL EXAMINATIONS. 
515 
Fig. 33. 
L22O30^ 
a on b', 
5703O' 
Fig. 34. P on P', IO 903 O' 
122 
30 
r _ P on «, 123 00 
112 
00 
a on e', 
109 
00 
P" on a, 126 00 
55 
40 
a' on g, 
122 
30 
IPj 'F 1 P' on h, 54 40 
71 
30 
108 
30 
The edge of the 
92 
30 
h on e'. 
128 
30 
plane h is seen at 
124 
30 
h' on/. 
125 
00* 
b in the figure.* 
The above measurements were made in March, 1832. Prof. Torrey, when I was engaged 
on those measurements, sent me the results of some measurements that he had made in 1826. 
He made the specific gravity | 4.33 ^ measurements were as follows : 
Fig. 35. 
OTonT, 1080 
m on D', 58° to 58^° 
T' on B', 
T on T^, 129J to 1 
m' on A, 58 
D' on T^, 
PonP^ 130 
mf on P, 58 
D on B', 
0 
0 
m on T', 58 
P on B", 
A on 131? 
m on D, 108 
A on T, 
m on B, 130 
m on P, 123 
m' on T', 123 
m' on D'', 122 ^ 
m on A, 122 f 
D on D', 123 
Some of the above measurements correspond with some of the modifications of the regular 
octohedron, in which one of the vertices is replaced by a plane, with another plane parallel to 
one of the diagonals of the base ; and as such, might be referred to franklinite, if its com¬ 
position would justify it. More of the angles measured correspond with modifications of the 
rhomboid of specular iron ore, to which it must undoubtedly be referred. 
* The letters used on these figures hove no reference to crystallographical notation. 
65* 
