derstanding of it. A simple illustration of this will prepare the way for more involved illustrations.
A few months ago, the Times gave us an account of the last achievement in automatic printing—the "Walter Press," by which its own immense edition is thrown off in a few hours every morning. Suppose a reader of the description, adequately familiar with mechanical details, follows what he reads step by step with full comprehension perhaps making his ideas more definite by going to see the apparatus at work and questioning the attendants? Now he goes away considering he understands all about it. Possibly, under its aspect as a feat in mechanical engineering, he does so. Possibly also, under its biographical aspect, as implying in Mr. Walter and those who cooperated with him certain traits, moral and intellectual, he does so. But under its sociological aspect he has no notion of its meaning, and does not even suspect that it has a sociological aspect. Yet, if he begins to look into the genesis of the thing, he will find that he is but on the threshold of the full explanation. On asking not what is its proximate but what is its remote origin, he finds, in the first place, that this automatic printing-machine is lineally descended from other automatic printing-machines, which have undergone successive developments—each presupposing others that went before: without cylinder printing-machines long previously used and improved, there would have been no "Walter Press." He inquires a step further, and discovers that this last improvement became possible only by the help of papier-mâché stereotyping, which, first employed for making flat plates, afforded the possibility of making cylindrical plates. And tracing this back, he finds that plaster-of-paris stereotyping came before it, and that there was another process before that. Again he learns that this highest form of automatic printing, like the many less-developed forms preceding it, depended for its practicability on the introduction of rollers for distributing ink, instead of the hand-implements used by "printer's devils" fifty years ago—which rollers, again, could never have been made fit for their present purposes, without the discovery of that curious elastic compound out of which they are cast. And then, on tracing the more remote antecedents, he finds an ancestry of hand printing-presses, which, through generations, had been successively improved. Now, perhaps, he thinks he understands the apparatus, considered as a sociological fact. Far from it. Its multitudinous parts, which will work together only when highly finished and exactly adjusted, came from machine-shops, where there are varieties of complicated, highly-finished engines for turning cylinders, cutting out wheels, planing bars, and so forth; and on the preexistence of these the existence of this printing-machine depended. If he inquires into the history of these complex automatic tools, he finds they have severally been, in the slow course of mechanical progress, brought to their present perfection by the help of