Where may these laws be found? Statutes passed by Congress are printed in the Statutes-at-Large, one or more volumes for each session. State statutes are printed in volumes known as Session Laws, or simply as Laws of Pennsylvania or Acts and Resolves of Massachusetts. From time to time, usually every ten years, these state laws are revised, rearranged, and consolidated into one general compilation, usually published as the Revised Statutes or Revised Laws. A similar publication is issued periodically containing the revised national statutes. City councils enact legislation by means of ordinances, which are put together in a volume of Revised Ordinances. When all the national or state laws relating to a certain subject (for example, criminal law, or civil procedure, or municipal affairs, etc.) are brought together into one compilation this is usually known as a code. Thus we speak of the Criminal Code or the Code of Civil Procedure or the Municipal Code. Footnote 146: In general, equity applies only to certain classes of civil actions and never to criminal cases; its procedure is simple; a jury is not ordinarily summoned to hear the facts; evidence in writing may be submitted; judgment is given by the issue of an order or decree and not by awarding a certain sum in damages. A further explanation may be found in the _Cyclopedia of American Government_, Vol. I, pp. 673-675. Footnote 147: Courts of law, in addition to awarding punishment in criminal cases and damages in civil cases are empowered to issue _writs_. Writs are orders or decrees commanding certain things to be done or left undone. They are addressed to other courts, or to public officials, or to individuals. The best-known of these writs is the writ of _habeas corpus_, an order issued to a jailor or other custodian commanding him to produce a person in court and show why he is held in custody. If the court finds that the person is wrongfully held in custody it orders his release. Another common writ is the writ of mandate (_mandamus_) issued to public officials to compel them to perform some duty which is imposed upon them by law. A _writ of error_ is issued in order to carry a case from a lower to a higher court. Footnote 148: In some county courts the grand jury is not now used (see p. 172). Footnote 149: These objections are called _challenges_. The judge decides whether they are well-founded. Both sides are usually allowed a certain number of _peremptory challenges_, that is, objections for which no reason at all need be given. Footnote 150: