colossal dimensions.

The lighting system that Edison contemplated in this entirely new
departure from antecedent methods included the generation of electrical
energy, or current, on a very large scale; its distribution throughout
extended areas, and its division and subdivision into small units
converted into light at innumerable points in every direction from
the source of supply, each unit to be independent of every other and
susceptible to immediate control by the user.

This was truly an altogether prodigious undertaking. We need not
wonder that Professor Tyndall, in words implying grave doubt as to the
possibility of any solution of the various problems, said publicly that
he would much rather have the matter in Edison's hands than in his own.
There were no precedents, nothing upon which to build or improve. The
problems could only be answered by the creation of new devices and
methods expressly worked out for their solution. An electric lamp
answering certain specific requirements would, indeed, be the key to the
situation, but its commercial adaptation required a multifarious variety
of apparatus and devices. The word "system" is much abused in invention,
and during the early days of electric lighting its use applied to a mere
freakish lamp or dynamo was often ludicrous. But, after all, nothing
short of a complete system could give real value to the lamp as an
invention; nothing short of a system could body forth the new art to
the public. Let us therefore set down briefly a few of the leading items
needed for perfect illumination by electricity, all of which were part
of the Edison programme:

First--To conceive a broad and fundamentally correct method of
distributing the current, satisfactory in a scientific sense and
practical commercially in its efficiency and economy. This meant, ready
made, a comprehensive plan analogous to illumination by gas, with a
network of conductors all connected together, so that in any given city
area the lights could be fed with electricity from several directions,
thus eliminating any interruption due to the disturbance on any
particular section.

Second--To devise an electric lamp that would give about the same amount
of light as a gas jet, which custom had proven to be a suitable and
useful unit. This lamp must possess the quality of requiring only a
small investment in the copper conductors reaching it. Each lamp must
be independent of every other lamp. Each and all the