This section is from the book "Popular Law Library Vol7 Equity Jurisprudence, Trusts, Equity Pleading", by Albert H. Putney. Also available from Amazon: Popular Law-Dictionary.
The regular process for appearance in equity, is the writ of subpoena, directed to the defendant, commanding him, under a penalty, personally to appear in court at a prescribed time, and answer the allegations of the bill. It issues in all original proceedings in equity immediately upon the filing of the bill.
Obedience to the subpoena may be enforced by attachment for contempt of court in cases where discovery is necessary from the defendant.