. . "By chapter 36 of 1792 (1 St. at Large, p. 276) it was provided, (section 2:) 'That the forms of writs, executions, and other process, except their style, and the forms and modes of proceedings in suits, * * * in those of equity and in those of admiralty and maritime jurisdiction [shall be] according to the principles, rules, and usages which belong to courts of equity and admiralty, respectively," . . .