thus reached must be corrected by deducting "1" (first adding 7,
if the total be "0"), if the date be January or February in a leap year;
remembering that every year divisible by 4 is a leap year, excepting only
the century years, in new style, when the number of centuries is _not_ so
divisible (e.g., 1800).

The final result gives the day of the week, "0" meaning Sunday, "1" Monday,
and so on.

EXAMPLES.

1783, _September_ 18.

17 divided by 4 leaves "1" over; 1 from 3 gives "2;" twice 2 is "4."

83 is 6 dozen and 11, giving 17; plus 2 gives 19, i.e. (dividing by 7),
"5." Total 9, i.e., "2."

The item for August is "8 from 10," i.e., "2;" so, for September, it is "2
plus 3," i.e., "5." Total 7, i.e., "0," which goes out.

18 gives "4." Answer, "_Thursday_."

1676, _February_ 23.

16 from 18 gives "2."

76 is 6 dozen and 4, giving 10; plus 1 gives 11, i.e., "4." Total "6."

The item for February is "3." Total 9, i.e., "2."

23 gives "2." Total "4."

Correction for leap year gives "3." Answer, "_Wednesday_."

LEWIS CARROLL.

* * * * *

PRECIOUS STONES OF THE UNITED STATES.

To the recently distributed government report on the mineral resources of
the United States for 1885.[1] Mr. G.F. Kunz contributes an interesting
chapter in which is recorded the progress made during that year in the
discovery and utilization of precious stones.

[Footnote 1: Mineral Resources of the United States: Calendar Year 1885.
Washington: Government Printing Office. 1888.]

In the summer of 1885, a remarkably large pocket containing fine crystals
of muscovite, with brilliant crystals of rutile implanted on them, was
found at the Emerald and Hiddenite Mining Company's works, at Stony Point,
N.C., and was sold in the form of cabinet specimens for $750. While the
soil overlying the rock was being worked, nine crystals of emerald were
found, all of which were doubly terminated, and measured from 1 inch to
3-1/8 inches in length and 1-2/3 inch in width. One of these crystals is
very perfect as a specimen, being of a fine light green color, and weighing
83/4 ounces. It is held by the company at $1,500, and the nine crystals
together at $3,000. Another of these crystals, doubly terminated, measures
21/2 inches by 11/12 of an inch, and is filled with large rhombohedral
cavities, which formerly contained dolomite. The only crystal from this
collection that has been cut into a gem was found