111 US 122 Black v. Thorne  111 U.S. 122  4 S.Ct. 326  28 L.Ed.
372  BLACK, Adm'r, and another THORNE and others.  March 24,
1884.  Chas. N. Black, for appellants.  D. B. Eaton, for
appellees.    This is a suit on the equity side of the court for
the infringement of two patents issued to the plaintiffs'
intestate, one for an alleged 'new and useful improvement for
burning tan bark, bagasse, sawdust, and other kinds of fuel, in
a wet state, for the purpose of creating heat to generate steam,
or to be employed in heating or drying operations;' and the
other for 'a new and useful improvement in furnaces, in using as
fuel bagasse and other carbonaceous substances, too wet to be
conveniently burned in the usual way,' with a prayer that the
defendants may be decreed to account for and pay to the
plaintiffs the gains and profits derived from making and using
furnaces containing the inventions and improvements of the
deceased, and be enjoined from further infringement. The
defendants contested the validity of the pat