cientific questions. One
party of observers say that this plant always points its leaves north
and south, the leaf standing edgewise to the earth and the two sides
facing to the east and west. This plant is found on the prairies and
plains, and is known scientifically as _silphium lacinatum_, popularly
as pilot weed, rosin weed, and turpentine weed. It stands from three to
six feet high, and the trappers and Indians are said to find their way
in dark nights by feeling its leaves. These assertions of polarity are
denied by the other party. Mr. Meehan now says that both are right.
When the leaves are young and small the pointing to the north is
unmistakable, but when they become larger, are beaten down by rains,
and weighted with sand and dew, they are not able to recover their lost
bearings.

BALLOONS IN METEOROLOGY.

Balloon ascensions are quietly but frequently used by scientific men
for the purpose of studying the upper parts of the atmosphere. Russian
savants have lately paid especial attention to this work, but have been
prevented from extending their examinations to any great height. Prof.
Mendeleef of St. Petersburg now undertakes to accomplish this also, and
devotes the profits of two books published by him to the construction
of a balloon. This is to have a capacity of two or three thousand cubic
yards, and will be filled by means arranged by him. France also pursues
this path of investigation with great vigor. Count Bathyani recently
took up a radiometer to a height of about a mile. At the earth it made
in the shade thirty-five revolutions per minute. At the height of 5,000
feet it made sixty-four revolutions, also in the shade. In the sun,
2,300 feet above the earth, it made fifty-four revolutions. Count
Bathyani also took up an ethereal apparatus for the purpose of
condensing water vapor at various heights, in order to collect the
microscopic particles floating in the air. This line of investigation
will be continued by means of an apparatus filled with methylic ether.
This will give a temperature of -20 deg. C., or -15 deg. Fahr. The
moisture will condense as ice which will be scraped off the vessels.
All the solid particles floating in the immediate neighborhood of the
apparatus will also be obtained.

THE LEAD PRODUCT.

The mining of lead is a business in which Americans are successfully
using the remarkable resources of this country. In 1866 the amount made
here was only 14,342 tons,