self. I might, of course, ring changes
on the steam-engine and the telegraph, the electrotype and the
photograph, the medical applications of physics, and the various other
inlets by which scientific thought filters into practical life. That
would be easy compared with the task of informing you how you are to
make the study of physics the instrument of your pupil's culture; how
you are to possess its facts and make them living seeds which shall
take root and grow in the mind, and not lie like dead lumber in the
storehouse of memory. This is a task much heavier than the mere
recounting of scientific achievements; and it is one which, feeling my
own want of time to execute it aright, I might well hesitate to
accept.

But let me sink excuses, and attack the work before me. First and
foremost, then, I would advise you to get a knowledge of facts from
actual observation. Facts looked at directly are vital; when they
pass into words half the sap is taken out of them. You wish, for
example, to get a knowledge of magnetism; well, provide yourself with
a good book on the subject, if you can, but do not be content with
what the book tells you; do not be satisfied with its descriptive
woodcuts; see the operations of the force yourself. Half of our book
writers describe experiments which they never made, and their
descriptions often lack both force and truth; but, no matter how
clever or conscientious they may be, their written words cannot supply
the place of actual observation. Every fact has numerous radiations,
which are shorn off by the man who describes it.

Go, then, to a philosophical instrument maker, and give a shilling or
half a crown for a straight bar-magnet, or, if you can afford it,
purchase a pair of them; or get a smith to cut a length of ten inches
from a bar of steel an inch wide and half an inch thick; file its ends
smoothly, harden it, and get somebody like myself to magnetise it.
Procure some darning needles, and also a little unspun silk, which
will give you a suspending fibre void of torsion. Make little loop
of paper, or of wire, and attach your fibre to it. Do it neatly. In
the loop place a darning-needle, and bring the two ends or poles, as
they are called, of your bar-magnet successively up to the ends of the
needle. Both the poles, you find, attract both ends of the needle.
Replace the needle by a bit of annealed iron wire; the same effects
ensue. Suspend successively little rods of lead,