stockings should be required, it would be an absurd waste of time, and of capital, to construct a stocking-frame to weave them, when, for a few pence, four steel wires can be procured by which they may be knit.  If, on the other hand, many thousand pairs were wanted, the time employed, and the expense incurred in constructing a stocking-frame, would be more than repaid by the saving of time in making that large number of stockings.  The same principle is applicable to the copying of letters:  if three or four copies only are required, the pen and the human hand furnish the cheapest means of obtaining them; if hundreds are called for, lithography may be brought to our assistance; but if hundreds of thousands are wanted, the machinery of a printing establishment supplies the most economical method of accomplishing the object.

330.  There are, however, many cases in which machines or tools must be made, in which economical production is not the most important object.  Whenever it is required to produce a few articles parts of machinery, for instance, which must be executed with the most rigid accuracy or be perfectly alike—­it is nearly impossible to fulfil this condition, even with the aid of the most skilful hands:  and it becomes necessary to make tools expressly for the purpose, although those tools should, as frequently happens, cost more in constructing than the things they are destined to make.

331.  Another instance of the just application of machinery, even at an increased expense, arises where the shortness of time in which the article is produced, has an important influence on its value.  In the publication of our daily newspapers, it frequently happens that the debates in the Houses of Parliament are carried on to three and four o’clock in the morning, that is. to within a very few hours of the time for the publication of the paper.  The speeches must be taken down by reporters, conveyed by them to the establishment of the newspaper, perhaps at the distance of one or two miles, transcribed by them in the office, set up by the compositor, the press corrected, and the paper be printed off and distributed, before the public can read them.  Some of these journals have a circulation of from five to ten thousand daily.  Supposing four thousand to be wanted, and that they could be printed only at the rate of five hundred per hour upon one side of the paper, (which was the greatest number two journeymen and a boy could take off by the old hand presses), sixteen hours would be required for printing the complete edition; and the news conveyed to the purchasers of the latest portion of the impression, would be out of date before they could receive it.  To obviate this difficulty, it was often necessary to set up the paper in duplicate, and sometimes, when late, in triplicate:  but the improvements in the printing machines have been so great, that four thousand copies are now printed on one side in an hour.