The oil-man's vade mecum; or, useful assistant. Shewing, ... the value of a tun of fish and seed oil, at any price per gallon; and the weight and value of any number of gallons, ... To which is added an appendix, ... By R.W. Whitton. - Whitton, R. W. (printed by M. Ritchie, for the author, and sold by H.D. Symonds; F. and C. Rivington,, 1799)