Screwed Chatons
Gold chatons serve as bushings for the bearing jewels. This used to be important for adjusting the vertical play of the wheels and pinions, but nowadays chatons play a primarily decorative role. Screwed gold chatons are found only on very high-quality watches. One can readily imagine how long it takes to polish the chaton and the screws, to heat each screw until it acquires precisely the same blue hue as the other screws and to assemble all the parts. The balance cock of this tourbillon watch has a diamond cap jewel – it’s another special feature that Lange uses only on its complicated watches.
1815 Tourbillon with Enamel Dial Platinum, 39.5 mm, manufacture Calibre L102.1, manual winding, 100 pieces
Relief Engraving
Lange uses additional decorative techniques to ennoble the limited special editions in its Handwerkskunst line. The elaborate relief engravings on the bridges allude to the starry decor on the enamel dial. In addition, as on antique pocketwatches, the tremblage technique is used to give a grainy finish to the plate’s surface. This chronograph movement also contains a particu- larly large number of steel parts, e.g., springs and levers, which Lange has decorated with a linear brushed finish. Like the bridges and plates, the steel parts also are beveled (i.e., their flanks are angled to exactly 45 degrees) and manually polished because no machine can produce the precisely angular shape of the inner corners.
1815 Rattrapante Perpetual Calendar Handwerkskunst White gold, 41.9 mm, manufacture Calibre L101.1, hand-wound, 20 pieces Images: Courtesy Brand