A public officer, whose duties are mainly other than judicial, may be invested with judicial power to be exercised only in certain causes which may be brought before him, in disposing of which he acts as a court. Such an one is a judge only when he is holding court. When it is adjourned, no court exists of which he could be a judge. Justices of the peace and parish judges are officers of this description. But ordinarily judges are appointed to hold some regular court, with stated sessions, which is always in existence. To such a judge considerable powers of a judicial nature are usually given for exercise when his court is not in session. The writ of _habeas corpus_, for instance, may be issued either by a court of record or by a judge of such a court, if applied for when the court is not in actual session. In the latter case, the return of the writ is made to him, the trial had before him, and judgment rendered out of court, or, as it is styled, "at chambers." While sitting for such a purpose, he may be regarded as exercising functions which really belong to the court and acting as a part of it. Statutes often, in case of a court having but a single judge, give him power to hold special courts whenever he may think proper. In such a case no very definite line is drawn between what judicial business the judge does and what the court does. While the proper and normal constitution of a court of record requires the attendance not only of a judge, but of a clerk and a crier or sheriff's officer, the only one whose presence is indispensable is the judge. A District Judge of the United States has this power of holding special courts, and is a court wherever and whenever he pleases to transact judicial business, whether he describes himself in such papers or process as he may issue, as court or judge.[Footnote: The U. S. _v._ The Schooner "Little Charles," 1 Brockenbrough's Reports, 382.] The judges of courts having equitable jurisdiction act often out of court in the issue of temporary injunctions. These are writs directing some one to refrain from doing a certain act. They generally direct it under pain of a specified pecuniary forfeiture; but whether they do so or not, disobedience is punishable also by arrest and imprisonment, being treated as a contempt of court. The need of an injunction is often immediate. It would be worthless unless promptly granted. When, therefore, no court having power to issue one is in actual session, there would be a failure of justice if the judge could not act to the extent of granting temporary relief. Whether the injunction should be made permanent is a subsequent question, to be determined after a full hearing by the court. It may, in urgent cases admitting of no delay, be issued _ex parte_, but ordinarily the defendant is notified and has an opportunity for a summary hearing, either orally or on affidavits, before action is taken.