nts, and thereby acquire the information in a
practical way, one example of which will make a more lasting impression
than pages of dry text.

Throughout these pages, therefore, I shall, as briefly as possible,
point out the theories involved, as a foundation for the work, and then
illustrate the structural types or samples; and the work is so arranged
that what is done to-day is merely a prelude or stepping-stone to the
next phase of the art. In reality, we shall travel, to a considerable
extent, the course which the great investigators followed when they were
groping for the facts and discovering the great manifestations in
nature.

CHAPTER II

WHAT TOOLS AND APPARATUS ARE NEEDED

PREPARING THE WORKSHOP.--Before commencing actual experiments we should
prepare the workshop and tools. Since we are going into this work as
pioneers, we shall have to be dependent upon our own efforts for the
production of the electrical apparatus, so as to be able, with our
home-made factory, to provide the power, the heat and the electricity.
Then, finding we are successful in these enterprises, we may look
forward for "more worlds to conquer."

By this time our neighbors will become interested in and solicit work
from us.

USES OF OUR WORKSHOPS.--They may want us to test batteries, and it then
becomes necessary to construct mechanism to detect and measure
electricity; to install new and improved apparatus; and to put in and
connect up electric bells in their houses, as well as burglar alarms. To
meet the requirements, we put in a telegraph line, having learned, as
well as we are able, how they are made and operated. But we find the
telegraph too slow and altogether unsuited for our purposes, as well as
for the uses of the neighborhood, so we conclude to put in a telephone
system.

WHAT TO BUILD.--It is necessary, therefore, to commence right at the
bottom to build a telephone, a transmitter, a receiver and a
switch-board for our system. From the telephone we soon see the
desirability of getting into touch with the great outside world, and
wireless telegraphy absorbs our time and energies.

But as we learn more and more of the wonderful things electricity will
do, we are brought into contact with problems which directly interest
the home. Sanitation attracts our attention. Why cannot electricity act
as an agent to purify our drinking water, to sterilize sewage and to
arrest offensive odors? We must, therefore, learn som