eet. The
projector may be pointed in all directions, so as to bring it to bear
in succession upon all the points that it is desired to illuminate.
The 12-inch projector is the smallest size made for this purpose.
The constructors, Messrs. Sautter, Lemonnier & Co., are making more
powerful ones, up to 36 inches in diameter, with a corresponding
increase in the size of the electric machines, motors, and boilers.

The various powers make use of these apparatus for the defense of
fortresses and coasts, for campaign service, etc.

The various parts of the apparatus can be easily taken apart and
loaded upon the backs of mules. The only really heavy piece is the
boiler, which weighs about 990 pounds.

* * * * *

ELECTRICITY AND MAGNETISM.[1]

[Footnote 1: Introductory to the course of Lectures on Physics at
Washington University, St. Louis, Missouri--_Kansas City
Review._]

Prof. FRANCIS E. NIPHER.

It was known six hundred years before Christ that when amber is rubbed
it acquires the power of attracting light bodies. The Greek name for
amber, _elektron_, was afterward applied to the phenomenon. It was
also known to the ancients that a certain kind of iron ore, first
found at Magnesia, in Asia Minor, had the property of attracting
iron. This phenomenon was called magnetism. This is the history of
electricity and magnetism for two thousand years, during which these
facts stood alone, like isolated mountain peaks, with summits touched
and made visible by the morning sun, while the region surrounding and
connecting them lay hidden and unexplored.

In fact, it is only in more recent times that men could be found
possessing the necessary mental qualities to insure success in
physical investigation. Some of the ancients were acute observers, and
made valuable observations in descriptive natural history. They also
observed and described phenomena which they saw around them, although
often in vague and mystical terms.

They, however, were greatly lacking in power to discriminate
between the possible and the absurd, and so old wives' tales,
acute speculations, and truthful observations are strangely jumbled
together. With rare exceptions they did not contrive new conditions to
bring about phenomena which Nature did not spontaneously exhibit--they
did not experiment. They attempted to solve the universe in their
heads, and made little progress.

In mediaeval times intellectua