It had never been tried over long distances in the open air, and many practical modifications had yet to be made, the necessity for which could only be ascertained during the actual construction of a commercial line.

Morse's first idea, adhered to by him until found by experience, in the building of the first line between Washington and Baltimore, to be impracticable, had been to bury the wires in a trench in the ground.

I say it was found to be impracticable, but that is true only of the conditions at that early date.

The inventor was here again ahead of his time, for the underground system is now used in many cities, and may in time become universal.

However, we shall see, when the story of the building of that first historic line is told, that in this respect, and in many others, great difficulties were encountered and failure was averted only by the ingenuity, the resourcefulness, and the quick-wittedness of the inventor himself and his able assistants.