A Machine for enifavirtg metallic Plate!, 7» 



the fole Agents employed to fpace the charasSlers. If the plate were not moved hj the- lever, 

 the impreffions would fall upon each other, and thus, for example, the letter i would be totally 

 obliterated by the impreflionof the letter /. 



Whenever, therefore, it is required to difpofe the letters / and / befide each other, th<? 

 plate muft be moved after ftriking the letter i through a fpace equal to the quantity of the 

 defired operation. Suppofe this to be one fourth of a line, and that the levier fhould run 

 through an arc of ten degrees to move the plate through this quantity : as foon as the pia 

 of the letter / fliall be adjufled to the nccellary length to enable the lever to defcribe an arc 

 of ten degrees, the operation of fpacing the two letters i and / will be reduced to that of 

 placing the laft letter beneath the fixed index, and moving the plate till the lever (hall be 

 ftopped by the pin belonging to the letter /. All the other letters will be equally fpaced, if 

 the difpofition of the punches in the wheel be fuch, that the laft ftroke of any letter fhalt 

 Confound itfelf with any letter of a fmgle ftroke, fuppofmg them to be imprefled one after 

 the other, without moving the lever between ftroke and ftroke. This arrangement deferves. 

 to be very ferioufly attended to, becaufe the procefs could not be performed without it.^ 



Many well informed perfons are of opinion, that the perfeiSl equality which this machine 

 for engraving affords in the formation of letters and figns the moft difficult to be imitated, 

 may afford a means of remedying the dangers of forgery. It is certain that the performance 

 exhibits a fimple and ftriking charafter of precifion, which is fuch, that the leaft experienced 

 eyes might flatter themfelves in certain cafes to diftinguifli counterfeits from originals. My 

 unfortunate colleague, Lavoifier, whom the friends of fcience and the arts will not ceafe to 

 regret, made fome experiments of this kind for the catjfe d'efcompte which were attended with 

 perfect fuccefs. Artifts appointed for that purpofe endeavoured, in vain, to imitate a vignette 

 formed by the fucceffive and equal motion of a chara£ler of ornament*. My firft machine 

 for engraving was executed by Carrochez,, with whom I had very much trouble, from the 

 affiduity with which it was neceffary to attend to his operations. I was more fortunate in the 

 conftrudlion of the fecond ; a Ikilful artift, Richer,, executed this for a lover of the arts,, 

 with a degree of intelligence which was altogether furprifmg, and he even rendered it more 

 perfect by the addition of a fnail. The third machine of this kind, which was intended for 

 the fabrication of affignats, is not finifhed. It is by the fame artiftu 



"While I was employed in the conftruftion and improvement of my machine for engraving,. 

 Condorcet engaged me to make ufe of, in a fliort memoir of the celebrated Dupati, a method 

 1 had imagined to compofe a large work with a very fmall number of types. I complied with^ 

 his demand, and prefented to the academy a polytype plate, entitled EJfai d'imprimerie, prefenti 

 a Pacademie des fctences le 8 Fevrier, 1786. 



The number of moveable caft types which I pofTeffed, was contained in a box of the 

 form of a book, and was fufficient to compofe only four lines. When thefe four lines were 



* Thi& argument feems to apply only upon thft Aippoiition of the machine itfelf,. being generally un- 

 known to the public.— N. 



compofedy 



