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« Dictionary Index « Definitions under R
The rose engine is, I believe, a French invention, and has long been used for turning ornaments on metal, for instance, watch cases and other articles of plate; it was afterwards applied to produce them to print from by the rolling press: during the sitting of the commission for inquiring into the best means for preventing the forgery of Bank Notes, about twenty years ago, Mr. Perkins introduced a specimen bank note which was partly executed by this machine; and the late Mr. Branston, then of the firm of Whiting and Branston, was, if I am not mistaken, the first to engrave by its means for letterpress printing, and the tickets and shares for the last state lottery were executed by it at Beaufort House. Its great value for the prevention of forgery is, that all circles, curved and angular lines produced by this machine are precisely similar to each other and true, however numerous, and however small or large; it would be next to impossible to produce the same designs, with the same accuracy, by the hand, and the operation would also be uncommonly tedious.
By the kindness of Mr Holtzapffel I am enabled to introduce into this work a number of different patterns; only one specimen of each individual apparatus is given. The patterns which are capable of being produced are almost endless, and depend on the skill and taste of the operator; the variations in the designs being caused by different chucks being used in the operation; and the combinations of the effect produced by each chuck, either in straight lines, circles, ellipses, or as a ground covering the whole surface, in many instances are very delicate and have a beautiful effect. The following enumeration shows how the annexed specimens were produced.
Figs. 1. 10. Holtzapffel and Co.'s compound oval and eccentric chuck — 1. Two eccentric movements; 10. One oval and one eccentric movement. 2. 6. 8. Ibbetson's geometric chuck, parts first, second and third. 3. Rose engine. 4. Straight line chuck. 5. Segment engine. 7. Oval chuck.
9. Eccentric chuck. 11. Eccentric chuck with the rose engine. 12. 15. Holtzapffel and Co.'s compound oval and-eccentric chuck with the rose engine: — 12. One oval and one eccentric movement; 15. Two eccentric movements. 13. Oval chuck with the rose engine. 14. Ibbetson's compound eccentric chuck. 16. Geometric chuck combined with the rose engine. 17. Straight line chuck combined with the rose engine.
For details and descriptions of the various chucks, with the methods of operating with them, the reader is referred to Manuel de Tourneur, published by Bergeron in 1792, and to “Specimens in Eccentric Turning, with Practical Instructions. By John Holt Ibbetson, Esq.” Third Edition, 8vo. London. [1840.]
Mr. Ibbetson observes, “The number of beautiful designs which may be obtained by combining, on this principle, two circular adjusting movements is inconceivable. Consecutive circles, &c. may be arranged, not only in elliptical curves, but in the shape of hearts — in straight lines — in triangles — in squares — in polygons, and in both inward and outward looped figures.”
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