8 J.D. Whitney on Minerals of the Lake Superior region. 
In the register from which the drawings were made, the blades revolve 
once in two feet; one hundred revolutions will therefore correspond to 
two hundred feet, or one division of the scale of the register to thirty- 
three fathoms. 
When the register is hauled up, the arms at gg, fig. 2, drop, and the 
springs cause the wheels to ungear and fly back, where they are held 
motionless by a projecting point at 2, fig. 3. The arms are ert ~ drop 
means of a small wire which is attached to the cap as s v7 
fig. 1; this wire is frstenad to, or hooks over the ends of dons arms, and 
when the register is drawn off, the arms fall. 
Mode of attaching the line to the register and specimen-tube——Before 
the line is put into the tube it is pier to the specimen-tube at a point 
four or five feet from the end of the line, the spare end is passed through 
the tube, and when the balls are all pee in the tube the extreme end of 
the line coming out at top is attached to the register, after taking a few 
turns round the top of the strap, the register being in its place. 
The line is thus attached to the register and specimen-tube only, and 
not to the large tube or weight. When the plummet strikes the bottom 
a part of the line will remain in the tube coiled; by hauling in the line 
-tube, and register; and by sai to haul in, the register 
and orange will be brought to the su 
The plummet on striking will, under most dibeumancal remain stick- 
ing in the mud in an upright position. 
a 
Art. II.—WNotice of New Localities, and ee varieties of 
Minerals, in the Lake Superior region: supplementary to the chap- 
ter on this subject, in Part II. of the Report of Foster and W hit- 
ney; by J. D. WHITNEY. 
Since the publication of the second part of our “ Report on 
the Geology of the Lake Superior Land ‘Sega in 1851, some 
materials, illustrative of the mineralogy of this region, have accu- 
mulated in my note-books, which, in the present communication, 
I have put together in the alphabetical order of the minerals 
noticed, for convenient reference. A few of the facts here stated 
were communicated to J. D. Dana, for the Jast edition of his 
“System of Mineralogy,” and are here re , with some ad- | 
bags pikes on the general mode of occurrence or econom- 
ort the ores and minerals mentioned. 
Be ater This mineral is quite abundant on Keweenaw 
Point, and i also been noticed by me on Michipicoten Island; 
it does not appear to have been observed in the Ontonagon re- 
gion. The finest locality, ‘however, by far, is at the Copper Falls 
a 
