484 TRANSACTIONS OF THE 



By the extraordinary power of the electrotype, an intaglio printing plate 

 can be readily produced from any photograph, and thousands of copies 

 multiplied, as in letter press. It has fully developed the art of nature 

 printing, which would never have been known but for it. Ordnance maps, 

 which are now so remarkable for their excellence, without its intervention 

 could not have been prepared. 



It is only by the agency of the wonderful electrotype that the charming 

 art of the historical engraver can be reproduced with fidelity from the 

 steel. And to the electrotype photography owes its multiplying power, 

 through the medium of a fixed plate. 



The most beautiful devices may be obtained for door plates, knobs, etch- 

 ings, from engravings, ornaments for spoons, forks, dinner plates, &c., by 

 electro-metallurgy, at a small cost. By its use copper may be thrown 

 down on an engraved plate very successfully, and when taken apart, the 

 plate, galvanized, will be a perfect copy in relief of the engraved one, 

 which will serve as a matrix for an infinity of impressions, fully equal to 

 engravings. Wood cuts, steel engravings, casts made of plaster, seals, 

 &c., may be admirably copied. 



By the galvano-plastic process, in two hours a coat of copper may be 

 made to cover, with the greatest imaginable accuracy, a colossal plaster 

 statue, giving it the solid appearance of the fiaest bronze. Copper may 

 thrown down upon moulds representing kettles, pans, urns, &., by the 

 action of galvanic electricity, in such a manner as to complete the article 

 without the aid of other artifice. 



If the agriculturist desires to illustrate the size or peculiarities of his 

 apples, pears, plums, potatoes, carrots, or pumpkins, he may coat them 

 with the thinnest imaginable covering of copper by electro-metallurgy. To 

 accomplish the object, cover the desired article with black lead, and thrust 

 a pin in the stalk or stem ; to this attach a wire, connect it with the zinc 

 of the battery, and place it in the solution, and complete the arrangement 

 by a piece of copper, which must be connected with the silver of the bat- 

 tery. The form, after the process, is perfectly characteristic, marking dis- 

 tinctly the individual characters of each. After having accomplished the 

 desired object, withdraw the pin, which leaves a hole sufficiently large for 

 the evaporating juices to pass out. Embossed surfaces may be copied 

 with the utmost facility, even if they consist of paper. It is necessary to 

 render them non-absorbent, by varnish, oil or wax. For paper, linseed oil 

 is probably the best. When ordinary type is to be electrotyped, each let- 

 ter is cast separately in a particular alloy, and, when combined together, 

 form words, and if they are intended to be kept for books having a large 

 circulation, a stereotype copy may be made of them. To accomplish which, 

 a plaster mould of the type is first obtained, which is baked in an oven 

 that it may be perfectly dry, and from this a metallic cast in stereotype 

 metal is made,' which is a copy of the original. It is presumed that a new 

 material, made of gum shellac and other substances, will be introduced to 



