Balance cock Small metal plate screwed to the visible side of the movement. It carries the balance wheel shaft bearing.

Blued steel, blued screws Steel parts are slowly and cautiously heated (annealed) to about 300°C. This process coats the metal with an extremely thin, shimmering film of cornflower-blue magnetite (Fe3O4).

Chamfering Also: angling, bevelling. The breaking and polishing of sharp edges on bridges and levers. The inclined surface has the same width along its entire circumference or length.

German silver Special alloy composed of copper and zinc, with a nickel concentration of about 10%. German silver is stronger than brass and has been traditionally used by Lange for the manufacture of plates and bridges. The addition of nickel minimises the oxidation of German silver and thus eliminates the need to electroplate the alloy - it can remain "untreated".

Glashütte ribbing A linear decoration. It is produced by a rotating grinding wheel that is slightly inclined and moved along the surface of the workpiece in parallel lines.

Gold chaton The gold setting of a bearing jewel - in Lange watches, chatons are often secured to the three-quarter plate with two or three screws.

Three-quarter plate The three-quarter plate was introduced in Glashütte by Adolph Lange in 1864. Since then, it has been a typical feature of Lange watches. It accommodates the counter-bearings of the going train and enhances the stability of the movement.

Whiplash precision index adjuster An adjusting device composed of a steel spring in the shape of a swan's neck, a pointer, and a setscrew. The screw is used to adjust the beat, or the timing, of the watch in very small increments.

Adolph Lange (1815-1875). Founder of the German precision watchmaking industry in Glashütte.

Escape wheel Together with the lever, it constitutes the escapement. It is the last wheel in the going train.

Screw balance A balance wheel that has adjustable screws and tiny washers along its rim.

Semi-oscillation Also: vibration. Half of the path travelled by the balance wheel from end point to end point.

Stop seconds Mechanism that stops the balance wheel and thus the movement of the seconds hand when the crown is pulled. This allows a watch to be precisely synchronised with an external time signal.

With the expertise and passion that already characterised the era of | Adolph Lange, the movement of the 1815 is finished to perfection in every detail. It unites practically all of the traditional and contemporary features of the Lange quality legacy in an astonishingly compact space. The | three-quarter plate made of untreated, cross-laminated | German silver and decorated with sleek | Glashütte ribbing is unmistakably Lange by origin. The plate is subtly accented with | blued screws, ruby-red | jewels and four screwed | gold chatons. All edges in the movement are | chamfered and polished, including the leaf spring of the | whiplash precision index adjuster. This patented adjustment system allows the rate of the watch to be corrected without the need to remove the balance. It is mounted on the small, hand-engraved | balance cock. The manually wound movement with | stop seconds has a power reserve of 45 hours when fully wound. The intricate, shock-proofed | screw balance executes 21,600 | semi-oscillations per hour and is adjusted in five | positions. Moreover, the | escape wheel, polished on both sides, is secured with a | black-polished steel end piece, a hallmark of classic horology.