ENGRAVING. 



ENLISTMENT. 



many way*, and their (eparate or combined employment can be to Tarl- 

 oiul jr modified by the distinct motions uf the carriage*, ftc., that a 

 practically unlimited number of pattern! can be produced, comprising 

 an endlew variety of curved, waving, and spiral line*, drawn with 

 mathematical precision. " The machine," obeerve* Mr. Henry Bradbury, 

 (who haa the exclusive poateasion of it in England,) " u *et in 

 motion by mean* of lever*, tooth-wheel*, and handle*, by which 

 the motive power ha* no influence whatever upon the correct- 

 ness and delicacy of the pattern*, properties infallibly guaranteed 

 by the arrangement of the machine. Owing to this simple manipu- 

 lation, the entire attention may be concentrated upon the cum position 

 of pattern*, offering a boundless field to the inventive spirit. In 

 spite of the many apparatus** and actions which combine to constitute 

 the Quilloche machine, the management of it i very simple. All the 

 portion* remain in constant connection with one another, and may, by 

 mean* of arrangement* of a very simple character, be immediately set in 

 motion, or (topped, a* circumstances may require." The machine itself 

 i* a angularly elegant piece of mechanism, and unlike the earlier 

 engraving machine*, it occupies a comparatively small space. 



ttedaiiir Exyraring. In 1880, M. Achille Collas invented a machine 

 for engraving representations of medals, coins, and other objects in 

 relief, which representations should afford to the eye a similar appear- 

 ance of relief to the medal itself. Shortly afterwards, Mr. Sexton, in 

 America, and Mr. Bate, in London, invented machines which effected 

 a similar object, and, as was said, without a certain " distortion " 

 inevitable in the old machine. A warm discussion was for some time 

 carried on between the advocates of the French and English machines, 

 and their respective merits even engaged the attention of a committee 

 of the House of Commons. 



The principle of all these machines is the same. The process of 

 copying medals by them may be familiarly illustrated by a reference to 

 that of the Silhouette or profile machine : that is, a pointer at one end of 

 a lever trace* over the object to be copied, and a pointer at the other 

 end executes the copy itself. We may suppose a medal to be laid 

 down flat, and that placed near it is the copper-plate on which the 

 engraving is to be made. A peculiar bent lever touches them both, 

 having a tracer-point at one end and an etching-point at the other ; the 

 tracer-point conies down vertically on the medal, whereas the etching- 

 point comes nearly horizontally into contact with the etching-ground 

 of the copper-plate. When the tracer-point passes over a flat or level 

 part of the medal, the etching-point marks or engraves a horizontal 

 line on the etching-ground ; but when the tracer rises over any of the 

 relief parts of the medal, the etching-point makes a curved line, more 

 or less convex in proportion to the boldness of relief. By passing 

 the tracer-point over every part of the surface of the medal, in parallel 

 line*, the etching-point is made to mark an equal number of lines on 

 the etching-ground of the copper-plate ; but these latter lines, instead 

 of being straight and parallel, have varying degrees of curvature. In 

 passing over a sloping part of the device on the medal, the lines in the 

 engraving become either more closely placed or more widely separated 

 than in the former case, according to the direction taken by the sloped 

 surface ; they thus give the light-and-shade appearance of a surface in 

 relief. In the original machines, M. Collas carried the tracing-point 

 over the medal vertically, Mr. Bate at an angle of 45, by which much 

 greater accuracy was ensured. Both these gentlemen subsequently made 

 several improvements in their machines ; and other machines, differing 

 in the details, have been invented. The latest, the most elegant as a 

 piece of mechanism, and the most compact, is that of Mr. Wagner, the 

 inventor of the Guilloche engraving machine, noticed above. Among 

 its advantage* are, the facilities with which by means of it " copies of 

 relief, in the same proportions as the model, in augmented or dimi- 

 nished proportions, reversed or otherwise, of more or less plastic 

 expression than the model, and of a different point of view, can be 

 produced." 



Electro-Magnetic En'/raving. Among the multiplicity of projects 

 which have been put forth for the employment of electro-magnetism, 

 have been several for producing engravings. The earliest machine of 

 this kind that we know of was one by Mr. Hansen, a German, in 1854; 

 one of the latest, that of an American, Mr. Brooman, in 1858. In these 

 machines, as in the engraving and medal machines above described, the 

 incision in the copper-plate is made by a graver working at one end of 

 a bent lever, or series of levers, corresponding in its motion with a 

 tracing-point at the other end, which is carried over the design to be 

 copied. But in these machines the action of the graver is produced 

 by the alternate making and breaking of contact, as is described 

 under ELECTRO-MOTIVE MACHINES. In Mr. Hansen's process, the 

 design is drawn on a metal plate, with a resined ink or other non- 

 conducting substance. In Mr. Brooman's, the pattern-plate is coated 

 with Tarnish or other non-conducting material, and the design is drawn 

 on it down to the metal. The tracing-point is made to travel succes- 

 sively over every part of the pattern-plate, and whenever it comes in 

 contact with a conducting surface the graver will be pressed down 

 upon the plate to be engraved, and the engraving process will go on 

 till the tracing point meets with the non-conducting surface, when 

 the circuit win be broken and the graver lifted off the plate. 

 This is continued till the whole of the design is passed over, when 

 a fac-simile of it will have been engraved. We are not aware that any 

 of these electromagnetic machine* have] been brought into practical 



operation : the idea i> ingenious, but Its successful application i* very 

 doubtful. 



PHotoyraphU Engraving. How to employ the Sun as an engraver, is 

 a problem which haa engaged the attention of many photographer* 

 and men of science in America a* well as in Europe. The mi<> 

 successful of their processes will be noticed under PHOTOGRAPHIC 

 KMORAVIHG. 



Reproduction of Plata. One of the earliest plans for reproducing 

 engraved plate* was that of Messrs. Perkins & Heath. A cylinder 

 of soft steel was passed over an engraved steel-plate, which had 

 been properly hardened, until it received the impression in relief. 

 The cylinder was then hardened, and being rolled upon a toft steel 

 plate, transferred to that a fac-simile of the original engraving capable 

 when hardened of yielding impression* as sharp a* the original plate. 

 Of course, the cylinder being very hard, several plates could be 

 thus taken from it The process has been largely employed for com- 

 mercial purposes, but not as far as we know for artistic work. For 

 both purposes, but especially for the latter a process equally effica- 

 cious and less likely to injure the original plate, was discovered in 

 the Electrotype, by which any number of repetitions of a copper 

 or even steel plate, of whatever size or delicacy of execution,- may 

 be produced with absolute safety and at comparatively small cost. 

 The process is described under ELECTRO-METALLURGY. It has been 

 extensively employed in the manufacture of bank-notes. 



The singularly ingenious Electro-Block process of Mr. Collins, by 

 which engraved fac-simile* of engravings or designs, of either the same, 

 a larger, or a smaller size, or of altered form, can be produced without 

 the aid of a draughtsman or engraver, is noticed under EARTHENWARE. 

 It is chiefly applied at present to the reproduction of blocks for 

 surface-printing, but it is also applicable to the reproduction of 

 incised plates. 



One of the moat recent applications of science to the art of engraving, 

 consists in coating the engraved plate with a thin film of some other 

 metal by means of the galvanic battery. Attention was first called to 

 this invention by M. Joubcrt who in 1858 took out a patent for 

 covering copper plates with an extremely thin coating of iron, a 

 process which he designated acieraffiiig. Plates so coated will yield, 

 he found, from 5000 to 9000 impressions ; and whenever it may appear 

 desirable, the printing can be stopped and a new coating be applied. 

 Mr. Henry Bradbury shortly afterwards published in the ' Journal of 

 the Society of Arts' (vol. vii. p. 172, ic.), a method he had employed 

 with success, for coating engraved plates with a deposit of zinc, by 

 means of chloride and cyanide of zinc, and a Smee's batten'. A plate 

 so coated he found will yield from 1500 to 2000 impressions; and 

 when it shows signs of wearing, the coating can be removed and 

 renewed at pleasure, with great facility and without injury to the 

 plate. He has since employed nickel, which yields 5000 impressions, 

 in the place of zinc, with equal facility, and with little additional 

 cost. 



ENGRAVINGS. [COPYRIGHT.] 



EX" GROSSING ; copying in a large hand ; the writing a deed in 

 fair, legible characters; from the French grossir, to make bigger. 

 Among lawyers it more particularly means the copying of any writing 

 fair upon parchment or stamped paper. 



Enyrosting also means the purchasing of large quantities of any 

 commodity, in order to sell it again at a high price. It was formerly 

 a very serious offence, but the statutes making Forestalling, Regrating, 

 and Ingrossing criminal, after being long in desuetude, have been 

 entirely repealed. (Blackst. ' Com.' Mr. Kerr's ed., vol. iv.) 



ENHARMONIC, the third in order of the three genera of ancient 

 music. The enharmonic genus of the Greeks was distinguished by 

 quarter tones, while the modern scale admits these small intervals 

 theoretically only, not practically, except by a fiction. Thus c sharp 

 and D flat are with the moderns practically the same note, at least on 

 keyed instruments, though, strictly, the former is JJ of the whole string 

 sounding c, the latter ft. The passage from one to the other of these 

 intervals is called an enharmonic change, and a change of key so effected 

 is designated by the term enharmonic modulation. Examples : 

 i . i - . I 



ENIGMA. 



ENLISTMENT, a voluntary engagement to serve as a private 

 soldier for a certain number of years, on receipt of a stipulated sum of 

 money. Enlistment differ* from enrolment, inasmuch a* it is a volun- 

 tary act, whereas the latter is, under some circumstances, rendered 

 compulsory : as in the case of men who are selected by ballot for the 

 militia in this country, or who have served in her Majesty's forces, and 

 are enrolled in the Reserve Force under the 22 A 23 Viet. c. 

 who are raised by conscription for military service generally on the 

 continent. 



