re 
- Wm. P. Blake on Lanthanite and Allanite. 245 
_ the sheet by a side propeller, so that the abscissas would be pro- 
epee to the spaces traversed, is very much the most desira- 
_ ble form, and possibly may not present too formidable difficulties. 
_ It would doubtless be best to experiment first with the barometric 
form; and if no unforseen obstacles occur, the greater object can 
then be maturely considered, and if practicable, fully realized, to 
_ the vast advantage of hydrography. 
Arr. XXXIL—Lanthanite and Allanite in Essex county, N. ¥.; 
by Wm. P. BLAKE. 
In this Journal, vol. xvi, Sept., 1853, I announced the occur- 
-Yence of carbonate of lanthanum at Bethlehem, Pa., associated 
with ores of zinc. At that place a mass of closely aggregated 
thin tabular crystals was taken out from an ochery soil overlying 
+a bed of calamine; but though diligent search has since been 
ad e same place, and at other points in the vicinity, not 
a single additional fragment has been found, and this interesting 
Species has continued to be almost as rare to mineralogists as 
when first described. : 
T have since found the mineral in the town of Moriah, Essex 
county, N. Y., at one of the openings on the great bed of mag- 
known as the “Sanford ore-bed.” It occurs in a 
~~ 
_ they vary in different specimens from white to a delicate pink or 
Tose tint, thus indicating the presence of didymium. 
_ The magnetite at this locality is associated with phosphate of 
lime (apatite) in small reddish-brown ¢ stals, known in that re- 
Sion as red sand. In portions of the bed it is the preponderating . 
a” and is disseminated in belts or layers parallel with the 
Walls, 
Allanite occurs abundantly along the plane of contact of the 
f ore with a mass of granitic rock which appears to be 
bed o 
_S10n or segregation in its midst. ; oo 
large surface of this granitic wall bare, and allanite crystals were 
found implanted upon it, in a dark red felds a 
_ 9re. The crystals are unusually large ane perfect, several of 
them, (of which, however, only fragments were obtained,) could 
SECOND SERIES, Vor. XXVI, No. 77.—SEPT., 1858. ae 
