Looking at Guilloche work in conservation

Brittany Nicole Cox and David Lindow

Abstract

Guilloche, also referred to as engine turning, is work produced on a rose engine or straight-line engine. The rose engine was developed in the 16th century, but found wide scale popularity in the early 19th century when Breguet applied the craft to augment his watch dials, cases, and movements. Many believe it reached its apex with Fabergé. Developing a conservation methodology for Guilloche work appears to be a relatively new subject and understanding the processes by which an object was made or decorated may be the first stage in development. Little information is widely available on the enigmatic rose engine and even less is available on the process by which its patterns are created. We will briefly explore the history of these machines and their various uses through examining the steps required for accomplishing distinct patterns and looking at some of the diverse objects that employ them. The reflective quality of Guilloche work along with the effects of oxidation on this property will be examined. Through this we will identify various pitfalls in the practice of cleaning and repair. The rose engine was employed not only in horology to decorate metal objects of art, but also in other media such as pottery by Josiah Wedgwood and modern plastic injection molding patterns. As these machines were used from the early 16th century through the present, many conservators are likely to encounter objects that were either made or decorated by them. This session will seek to aid in the development of a conservation methodology for treating and working with engine made or decorated objects.