ROSE-ENGINE. 



The back puppet, L, is made of caft-iron, and is fitted upon 

 the caft-iron bearers, on which it can be fixed at the re- 

 quired diftance from the mandrel by a vertical fcrew under- 

 neath, and a nut, which comes in contact with a horizontal 

 plate or wafiier below the faid bearers. Itscentrefcrewhasa 

 fharp conical point to fapport the work, and there is a clamp- 

 fcrew at top to fallen the centre-fcrew, to prevent it from 

 running baek. 



The methods of fixing the work to the end of the mandrel 

 whillt it is turned are very numerous, and vary in almoit every 

 inltance : in general, it is held in a piece of wood, I, called a 

 chuck, which is fcrewed upon the nofe of the mandrel T, 

 and being bored, or turned out in the manner of a cup, the 

 piece of wood or ivory which is to be turned its driven into 

 it by a mallet till it is firmly fixed : the wood is, of courfe, 

 cut nearly to a circular figure, before it is fixed in the chuck ; 

 it is then wrought with a (harp triangular pointed tool, l>, 

 which being fixed in the reft, and advanced to the work by 

 the fcrew ;', cuts fmall contiguous grooves on the furface, 

 till it has broken the grain of the wood, and removed all 

 exuberances. The tool being gradually advanced by its 

 fcrews d and i, as is required, the work is reduced at 

 length nearly to its intended fize and figure, but will be 

 wholly covered with fmall grooves : to remove thefe, and 

 render the work even, another tool is next ufed ; this is 

 formed like a narrow duffel, but made very thick, and with 

 an obtufe edge, which is only bevelled on the under fide : 

 its edge will remove the eminences between the grooves left 

 by the firft tool. The work is then fmoothed, by applying to 

 it the edge of a piece of the blade of a broken knife bevelled 

 away ; this is held in the hand, and the work is followed up 

 with it, that its fharp edge may fcrape away any roughnefs 

 left by the tools. To polifh the wood, a piece of feal-fkin, 

 Dutch reed, or glafs paper, is held by the hand upon the 

 work as it runs round, and it cuts away a fine powder, mak- 

 ing the work fmooth enough to receive a polifh. This is 

 raifed by firft applying a piece of bees-wax, till the work is 

 flightly covered with it, then afterwards burnifhing or 

 polifhing it, by holding a fiat piece of hard wood upon it. 

 The finifh can be given by the friction of a coarfe woollen 

 rag, lightly fmeared with olive oil. 



Ivory is turned nearly in the fame manner, but is polifhed 

 with chalk and water, and afterwards by the friction of a 

 woollen cloth ; or, if it is firft touched with an oily rag, and 

 rubbed off with a dry woollen cloth, it will have a very fine 

 furface. 



This is only the fame procefs as is ufed for ordinary turn- 

 ing ; but when the work is finifhed in this manner, the orna- 

 menting is began by releafing the bolt, 2, of the mandrel- 

 frame G H, and chufing the rofette beft adapted to the 

 pattern which is required. The piece, n, is fet upon the tri- 

 angular bar, to be in contact with its wave, and will thus give 

 the ofcillating motion, as before defcribed ; fo that when the 

 tool is applied to the work, it will produce a waved or in- 

 dented furface, or outline, correfponding with the figure 

 of the rofette, inftead of the circular figure produced by the 

 common lathe. 



If the ornamenting is to be performed upon a flat furface, 

 fuch, for inftance, as the lid or top of a box, it is chucked, 

 as (hewn inftg. 6, and the point of the tool being applied to 

 it, will cut a waved line. To do this more conveniently, 

 the Aider, g , is advanced to the work, by preffing it with 

 the hand inftead of the fcrew i ; for, by lifting up a fmall 

 fpriDg catch, of which the tail is feen plainly at 3, _/ff- 6, 

 the Aider is releafed from the nut of the fcrew i, which has 

 no other attachment to the Aider than by a tooth on this 

 catch entering into z notch in the nut, and it is prefled into 



the notch by a fcrew /. Now, by releafing the fcrew /, 

 lifting up the catch 3, and drawing back the Aider, the 

 tooth of the catch falls behind the nut of the fcrew, in- 

 ftead of being in the notch ; it will, therefore, form a 

 flop, to check the advance of the tool, though it allows it 

 to be drawn back to clear the work, and alfo to be pufhed 

 up towards it by the hand, to cut the line, the flop regu- 

 lating the depth of the line, as the hand can advance the 

 Aider no farther when it meets the nut. 



In this manner, a waved line is engraved round the edge 

 of it, fuch as is Aievvn in Jig. 9, the breadth of the line being 

 determined by the depth to which the point ot the tool is 

 regulated to penetrate, by turning the fcrew i. The outer 

 line being thus finifhed, the tool is now withdrawn to clear 

 the work, and the fcrew, d, of the great Aider being turned 

 a fmall quantity, the point of the tool is brought nearer to 

 the centre of the work ; here, by puthing up the tool, an- 

 other line is defcribed ; then a third within the fecond, and 

 fo on, at equal diftances, until they reach the centre : this 

 makes a very pretty ornament, as in Jig. 9. It fhould be 

 obferved, that as each line has the fame number of waves, 

 or indentations, they will neceffarily grow very fine as they 

 approach towards the centre ; but at the fame time as the 

 deviation from the circular figure is equal in the fmalleit as 

 well as the largeft rings, it follows, that the curves of the 

 waves of each ring, or line, will vary in a very gradual and 

 pleafmg manner, being Aightly curved at the circumference, 

 and more rapidly towards the centre. This pattern admits of 

 great variety, by employing different rofettes, fine or coarfe, 

 concave or convex ; but it will always have the waves included 

 in itraight lines directed to the centre. A very pretty varia- 

 tion is made by turning the rofette round upon the mandrel a 

 very fmall quantity every time before a frefh line is defcribed. 

 For this purpofe, the rofettes are not fixed fall upon the 

 mandrel, but are fitted thereupon, fo as to admit of turning 

 round, being moved by a fmall fcrew at the end towards 

 H. As an example of the ufe of this movement,^. 10. is 

 given, which confifts of a rofe of twenty-four waves. In 

 this, after drawing the exterior line, in the fame manner as 

 the former, when the Aider is fet for the fecond, the rofette is 

 turned round upon the mandrel a quantity equal to one- 

 fourth of a wave, or one-ninty-fixth part of the whole cir- 

 cle : thevcircle is now defcribed, and its waves will not fall 

 exadtly within thofe of the former, but a little advanced 

 therefrom. The next time a circle is to he drawn, the ro- 

 fette is again drifted, and fo on. As thi6 is a quantity equal 

 to one-fourth of the fpace between the waves, it is plain 

 that at every fourth line the waves will fall in lines drawn 

 towards the centre. Still this will not affeft the ap- 

 pearance, which will be totally different from the former, 

 {Jig. 9.) and very fuperior to it. The concentric lines, in 

 either of thefe patterns, are made exaftly at equal diftances, 

 by means of the divifions before-mentioned, upon the Aider 

 K, or otherwife by divifions made upon a head, which is 

 fitted upon the end of the fcrew d; and the rofettes are fet 

 exactly to the quantity they are intended to be turned 

 round, by means of divifions made upon the edge of a cir- 

 cular plate, which is tiled faft upon the mandrel, towards 

 the end H, and a line or mark upon the laft rofette applies 

 to it. The fcrew which effects the movement is fup- 

 ported in bearings upon this plate, and acts in the teeth of 

 a wheel, fixed within the hollow of the laft rofette. By this 

 means, when the fcrew is turned round by a key, it 

 caufes all the rofettes to turn round together any quantity 

 which the divifions on the circle indisate. On this prin- 

 ciple, great varieties of patterns may be made, and they 

 may be greatly diverfified by fhifting the rofettes alter- 

 1 1 nately 



