Diagrams I and J represent the appearance of counterfeit Medallions when magnified. K represents the appearance of a genuine Medallion as magnified 10 to 15 times. _Every line is full length_, and exactly of the _same size_. In J the lines _break off_ and _fork together_ all through the midst of the pattern, and some lines a little _coarser_ than others, which gives it a scratchy appearance. Whenever there are two or more medallions in a genuine bill that pretend to be alike, they are always exactly alike; being double-transferred from the same original die; (see medallion heads marked ‘3’ in the steel plate,) but two medallions cannot be made exactly alike separately by hand. The following extract in relation to this work is quoted from the Mechanic’s Magazine, 1835: “The Journal of the Franklin Institute for September contains an elegant engraved portrait of Wm. Congreve, the dramatist, executed by Wm. A. Spencer of Philadelphia, in the manner described, and has inserted the following proofs that the invention can be claimed for America. ‘Believing that the credit of the invention of a machine for medal ruling is due to America, we will briefly set forth our proofs, and then speak of the improvements which of late years the method has undergone. The proofs to be given of the existence and state of the machine are to be derived from the results produced by it. In 1817, by the use of a machine which had been invented in Philadelphia, Christian Gobrecht, die-sinker, produced an engraving upon copper, from a medal having upon it the head of Alexander of Russia. From this engraving impressions were taken and distributed. One of these impressions we have seen. In 1819, Asa Spencer, now of the firm of Draper, Underwood & Co. bank-note engravers, took with him to London a machine of the kind above alluded to, which was designed principally for straight and waved-line ruling. This machine was used in London during the year just mentioned, and the mode of ruling waved lines, and of copying medals, was then exhibited and explained by Mr. Spencer to several artists--particularly Mr. Terrell, who took by permission a drawing of the machine, for the purpose of having one made for his own use. Little however was done in the way of medal ruling until about three years since, (1832,) when a desire to apply the method to the engraving of designs for bank notes caused it to be revived by Mr. Spencer, who bestowed great attention upon it, and overcame the difficulties met with in the onset.’--The peculiar construction of this machine has never been made a secret, nor has it ever been patented, although prudential motives have required that it should not be minutely described, and thus be placed in the hands of those by whom its use might be perverted. The operations performed by this machine are the ruling of parallel straight lines at any required distances apart, either continuous or broken; ruling converging straight lines; ruling