It defies all metaphors and comparisons.

It cannot be shown by photography, not even in moving-pictures, because so much of it is concealed inside its wooden body.

And few people, if any, are initiated into its inner mysteries except those who belong to its own cortege of inventors and attendants.
A telephone switchboard is a pyramid of inventions.

If it is full-grown, it may have two million parts.

It may be lit with fifteen thousand tiny electric lamps and nerved with as much wire as would reach from New York to Berlin.