A payment reserved by the grantor of a patent, lease of a mine, or similar right, and payable proportionately to the use made of the right by the grantee. See Raynolds v. Hanna (C. C.) 55 Fed. 800; Hubenthal v. Kennedy, 76 Iowa, 707, 39 N. W. 694; Western Union Tel. Co. v. American Bell Tel. Co., 125 Fed. 342, 60 C. C. A. 220. Royalty also sometimes means a payment which is made to an author or composer by an assignee or licensee in respect of each copy of his work which is sold, or to an in- ventor in respect of each article sold under the patent. Sweet