Mistakes in copying are further diminished by placing a card or sheet of paper above the line which we are transcribing,--a device which saves the eyes the strain of finding the place on the page every time we look up from the notebook. Never fail to accompany each extract copied into the notebook with the authority from which it is taken. If from a book, give author, title, date of publication, volume and page. If from a public record or document, give volume and page, with the office or society, the town or city where the original is deposited. Along with extracts from books, it is well to note the library where they were consulted. We may wish to refer to the books again, and are likely to forget in which of the libraries we found them. After making an extract, compare it with the original, to guard against errors in copying. The true method of genealogical investigation is to follow as far as possible the methods of the lawyer. Not, indeed, that genealogical research has anything to do with the learned quibbles of a legal dry-bones! Far from it. But the genealogist may well proceed as would a lawyer whose case could only be won for his client by demonstrating a line of descent. The value of the legal method lies in the fact that it proceeds, step by step, toward the accumulation of _positive proofs_. If the demonstration of an ancestral link depends upon recorded wills, the lawyer will obtain certified copies of such wills, to be presented in court as evidence. If the proof lies in a deed, which perhaps demonstrates the relationship of husband and wife, or father and son, a certified copy of the deed is secured. If the family record be found in a Bible, and the book itself cannot be obtained for presentation in court, the record is copied and certified, and the history of the ownership of the book established by personal testimony or affidavits. In the same way extracts from church registers and tombstones are authenticated before a notary public or justice of the peace, and personal testimony is collected in the form of affidavits. Then, even if the originals should be destroyed, the copies are just as valuable as legal proofs. Every link of the chain is thus established. The lawyer knows that in the attempt to break down his case no cunning in cross-examination will be spared, no expedient of rebuttal left untried. He gathers the testimony of his witnesses, and also collects evidence of the credibility of these witnesses. Judge and jury will not only hear the testimony, but will form a judgment of the reliability of those who give it.