II 



GOU^LACE MANUFACTURE. 



GONIOMETER. 



BO uch piooesses bar* actually succeeded a* substitute* for gold- 

 lac* made on the mechanical intern above described ; but we shall 

 presently hre to notice one applicable to other purposes. 



Silver" Uee is made by plating silken thread with a flattened wire 

 of wlvrr. The processes are analogous in principle to those just 

 described, but of course less elaborate and lest costly. 



Pibrt-yiUimg.The gilding of fibre has lately occupied a good deal 

 of attention. Chemists and manufacturers hare long sought for a 

 mode of coating fibres quickly with gold by some chemical process, 

 as a substitute for the slower and more costly mode of fibre-plating. 

 The French government several years ago offered a price to the 

 inventor of any such process; but no one earned it by success. 

 Electro-metallurgy then seemed to open a new path, and many in- 

 genious researches were made ; but it was found that, although gold 

 could easily be made to attach itself to the thread, the thread was long 

 in drying through being sosked with a solution, and dried without 

 lustre ; while the foundation was too soft to admit of burnishing. In 

 short, the brilliancy of gold-lace was not at all imitated by this 

 product. 



After many chemical experiments, Mr. Albert Hock succeeded in 

 devising a mechanical contrivance. It is requisite that the silk should 

 be of superior quality, free from knotty nibs and rough places ; that 

 the gum should be boiled out of it ; and that the silk be dyed to a 

 light orange tint. The silk thread is wound on bobbins ; and when 

 about to be gilt, it is transferred to a brass roller, around which it is 

 wound so carefully ss to admit neither of interstices nor overlapping. 

 In its passage it passes through a trough containing a glutinous but 

 transparent liquid. Leaf-gold is then laid on the coil of gummed silk, 

 in pieces between three and four inches square ; the cylinder being 

 made to rotate partially to aid this application. Leaf after leaf is 

 applied, until all the silk is covered. The gold is then pressed down 

 upon the silk by a piece of cloth or wash-leather fastened to a piece of 

 wood. Oue side of the silk thread becomes thus gilt. To gild the 

 entire thread, it is transferred to another cylinder : during the passage 

 the gilt side necessarily winds next to the brass on the second cylinder, 

 leaving the ungilt part of the thread exposed, to be treated in the same 

 manner. If it is desired that the woven fabric should present a rich 

 alternation of gold and colours, the silk thread can be dyed of any 

 colour chosen, and only one side or half of it covered with gold. The 

 finished thread is wound upon boards or planchettes, ready to be 

 applied to weaving, lace- making, fringe-making, or any other purpose. 

 The advantages of this gilt fibre over gold lace are that the material is 

 light and pleasant for garment fabrics ; and that, owing to its lightness 

 and perfect flexibility, it can be wound and woven with perfect 

 facility. The disadvantage is, that it cannot be made to present the 

 brilliant and dazzling effect of thread plated with gold. As regards 

 cost, it is said that the finest plated thread, selling at 8.. per ounce, 

 measures 550 yards to the ounce ; anil that gilt thread of equal fineness 

 and length, but weighing only one- third of an ounce, sells at 5*. The 

 gilt fibre is dearer than the plated when estimated by weight, but 

 cheaper when estimated by length. Although good gold is necessary 

 for the best work, any combination of gold and silver, gold and copper, 

 silver and copper, or all three, would suffice, if applied in the form of 

 leaf. In some varieties of gauze scarfs the leaf metal used is wholly copper. 



Mr. Hock's method of fibre-gilding is not the only one practised. 

 Mr. Green obtained a patent in 1853 for a mode of covering thread 

 with gold, ultramarine, emerald green, and various kinds of coloured 

 powders. He employs metallic powders in the following way : The 

 thread is first dyed in the usual way ; then wound upon a reel ; then 

 passed rapidly over a gas-flame to singe off loose filaments ; then passed 

 over a roller which dips into a trough of transparent gum ; and then 

 between pads of leather to remove any superfluous gum. Thus far 

 prepared, the thread passes over a roller which dips into a trough con- 

 taining gold powder or any metallic colour in a pulverulent state ; by 

 which means it becomes coated with a very thin metallic layer. After 

 this the layer is dried. In one variety of the process the gumming 

 compound is mixed with the metallic powder, instead of being applied 

 previously to the thread. A slight degree of polish is given to the 

 gilt thread by passing it between highly-polished steel rollers. 



Other inventors have been at work in the same direction. The 

 Prussian Industrial Association offered, for many years consecutively, a 

 prize of 1000 thalers and a gold medal to any one who should invent an 

 effective mode of gilding silk, on condition ths/ the silk underwent no 

 alteration in other respects. After many unsuccessful competitive 

 attempts, Dr. Kroning of Stolberg gained the prize. The method he 

 invented is applicable either to woven or unwoven silk. The exterior 

 metallic surface is brilliant, and yet the thread remains perfectly 

 flexible. When soiled, the thread or fabric may be washed in soap 

 and water, and pressed lightly before drying. 



Electro-gilding, we have said, has not yet been rendered applicable 

 in the guU-lace manufacture. There is one invention, however, by 

 M. Burot, which relates to the gilding of woven stuffs. The textile 

 material to be gilt, whether made of silk or any other fibre, is dipped 

 into a solution of nitrate of silver and ammonia. After remaining in 

 this solution about two hours, it is taken out, and, when dry, exposed 

 to a current of pure hydrogen gas, which reduces the salt, and leaves 

 the silver in a metallic state on the stuff. A silvered surface is thus 

 obtained, which can easily be coated with gold by the electro-metallic 



process. Oilt and silvered fabrics of considerable beauty are thus 

 produced. 



GOLD-LEAF ELECTROSCOPE. [ELKCTBICITY, COMMON ; ELEC- 

 TROMETER.] 



GOLDEN FLEECE. [AROOXAOTS.] 



GOLDEN NUMBER, so called from its having been formerly 

 written in gold letters in the almanacs, is the year of the cycle of nine- 

 teen years in which the current year falls. To find it, add one to the 

 year of the Christian era, and divide by nineteen, the remainder is the 

 golden number of the year ; but if there be no remainder, then nine- 

 teen is the p..],l, n mmiU i . For the derivation and use of this number, 

 see PERIODS or REVOLUTION; METOICIC C. 



GOLDEN RULE, a name given to the rule of three, from iU 

 universal use. [PROPORTION.] 



OOMER CHAMBER. [CHAMBER.] 



GO'NDOLA is the name given to the pleasure-boats at Venice, 

 which are very numerous, and serve as a substitute for the coaches and 

 carriages of other cities. The town being built on many little islands, 

 divided by numerous canals, people of every condition are obliged to 

 make frequent use of the gondola, in order to proceed from one district 

 t<. another. The gondola is shallow, long, and narrow, pointed both at 

 the head and stern, and rowed by either one or two men. It is gene- 

 rally from 25 to 30 feet in length, and 5 feet in width in the n 

 where a square cabin is constructed for the use of the passen^-. The 

 cabin is furnished with commodious seats, and has glazed windows and 

 black curtains. By a law of the ancient republic, these cabins' were 

 uniformly covered with black cloth and hangings, and the gondolas 

 themselves painted black ; no distinction of ornaments being allowed, 

 except with regard to the gondolas of foreign ambassadors on the occa- 

 sion of public ceremonies. The gondolier! , or boatmen, formed an 

 important body or corporation, amounting to several thousands : they 

 were famed for their wit, often licentious, as well as for their skill and 

 honesty. Since the fall of the republic the number of gondolas has 

 greatly diminished, owing to the decrease of the population anil its 

 reduced fortunes. Byron, in his ' Beppo,' st 19 and 20, describes the 

 singularly dark appearance of the gondola, " just like a coffin clapp'd 

 in a canoe." 



GONFALO'NE, GUNTFANO'N, a word of Teutonic origin, derived 

 from ijunil, which in the Prankish and Vandalic dialects meant " war," 

 or " fight," and fano or faJine, which in German means a " flag " or 

 " standard ; " the two together mean a " flag of war." ( Wachter, 

 ' Glossarium Germanicum,' art. " Gund ; " and Ducange, art. " Gunt- 

 f.ino.") Both the French and Italians of the middle ages adopted the 

 word, and the latter corrupted it into " gonfalone," and called the 

 officer whose duty it was to carry the ensign "gonfaloniere." We read 

 of the gonfaloniere of the Holy Church, who was the commander-in- 

 chief of the papal forces. The title of Gonfaloniere di Qiustizia was 

 given to a high magistrate of the republic of Florence, appointed l>y 

 the constitution of 1'2'J2. [DANTE, in Bioo. Drv.] The republics of 

 Siena and Lucca had also magistrates called gonfalonieri. 



GONG, a Chinese musical instrument of percussion, made of a 

 mixed metal of copper and tin, in form much like the cover of a large 

 culinary caldron, being circular, varying from about 1 5 to 20 inches in 

 diameter, and having a rim of from 2 to 3 inches in depth. It is struck 

 by a kind of drum-stick, the head of which is of hard leather. The 

 sound or sounds of this instrument for it produces many jarring ones 

 simultaneously can hardly be called musical ; and in fact the gong, 

 which is very powerful, is only used for the purpose of making sonorous' 

 signals, of marking time, and of adding to the clangor of the martial 

 instruments used in war. 



GONIO'METER (from two Greek words yayla, an angle, ptrpor, a 

 measure) is the name of an instrument employed to determine the 

 angles at which the planes of crystals are inclined to each other. 

 [ANGLE ; PLANE.] The principle of the common goniometer is simply 

 this. It may easily be shown that if two right lines intersect one 

 another, the opposite angles thus formed will be equal. Hence, 

 regarding the point of intersection as a centre, about which either of 

 those right lines is free to revolve while the other remains fixed, if we 

 suppose one of the edges of a solid bounded by plane surfaces to be 

 applied to that centre, so that the edge may be perpendicular to the 

 plane in which the two right lines are situated, and then suppose the 

 lines to coincide with the two contiguous planes of the solid, it will be 

 evident that the divergence of the lines will be the measure of the 

 inclination of the planes. A graduated arc being now adjusted to the 

 line which we supposed fixed, the position of the other line would 

 indicate the number of degrees at which the planes of the solid were 

 inclined to each other. As this instrument, however, when applied to 

 laminated substances, such as crystals, is incapable of affording results 

 sufficiently accurate to determine the species to which the crystal 

 belongs, in consequence of the frequent irregularity of t)i<> fr:t< tm. ami 

 the ordinary minuteness of the planes, we shall, without dwelling 

 longer upon its construction, proceed to describe the more perfect 

 instrument invented by Dr. Wollaston, and called the r</ 

 goniometer. 



It is well known that a ray of light falling upon a polished plane is 

 reflected at an angle equal to the angle of incidence, and that to an eye 

 (situated in the direction of the reflected ray the object from which the 

 ray emanated will appear as much below that plane as it is really above 



