"Our United States greenbacks? Those are engraved and printed, my son, at the United States Bureau of Engraving and Printing at Washington. They are made from very fine and exquisitely prepared plates and printed on a special sort of paper. This paper has numberless little silk threads running through it which not only toughen it and prevent it from tearing but also make it almost impossible to duplicate. A counterfeiter would have to go to a deal of trouble to imitate such material." Paul nodded. He had noticed the blue threads in his fifty-dollar bill. In fact, there was not much about it that he had not noticed while twisting and turning it in his fingers. "Yes," continued his father, "our paper money and government notes are fine examples of accurate and perfect workmanship. I suppose, as they pass through our hands, we seldom consider the labor that goes into making them. From the time the designer begins his work to the moment the plates are made, tried out, and accepted, many, many hours of toil are consumed. You know, of course, that our government runs a very extensive printing plant where it uses tons of paper every year. There is no end to the government printing. The Congressional Records must be printed and filed, as must also thousands of reports from various boards and committees. Then there is stationery for official use; official documents of all sorts; catalogues; cards for government business." "I never thought of that." "Yes, indeed. Uncle Sam runs quite a jobbing office, all the details of which must be carefully systematized, too. Great care is taken that the spelling abbreviations and such details shall be uniform on all government documents. You can readily see how necessary it is that they should be. Therefore the government issues a manual for the use of its employees, a list of punctuation and capitalization marks and rules, as well as printers' marks which shall serve as a standard and must be conformed to for all government purposes." "That is interesting, isn't it?" murmured Paul. "You can readily understand that in preparing government reports and such things for the press a uniform abbreviation for the States, for example, must be used. It would be out of the question to have one person abbreviating Alabama one way and another person another. It would not only result in a slipshod lot of documents but the variation might mislead those who read it. In all such documents every detail must be the same. Moreover, often employees are far from being expert in such matters and a book to which they can refer is a great help to them. In addition, it settles all disputes arising between the clerks who make up the reports and the printers who print them; and it saves the time and labor of correcting errors." "I see."