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 oth- er 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: