The Spring Case Tourbillon is a tour de force wristwatch and a leading example of Daniels’ gloriously hand-crafted creations that incorporate the various inventions he made. Daniels only made two unique wristwatches for his own personal use; one of these being this exact novel double-dialled spring case watch with one-minute tourbillon and calendar, completed in 1992. Simple in its appearance, the double-dialled watch is technically impressive; from both its movement and dial display but also to its surprising spring case, enabling the watch to be popped open to reveal the back dial. The watch features exquisitely hand guilloché silver dials in the classic Daniels manner with eccentric gold chapters showing hours, minutes, and interlaced seconds, with a subsidiary for power reserve indication. The reverse dial shows the calendar indication and visible tourbillon escapement. The ingenious two-part case has an inner section holding the movement, which is hinged to the outer, so that when released by a pusher in the band it springs open to reveal the reverse dial. To affect this neatly, the winding crown is cleverly positioned between the lugs. The tourbillon had already become a signature element of Daniels work, rotating in one-minute and featuring his slim Co-axial escapement. Daniels’ invention of the Co-axial escapement in 1975 was subsequently fitted to all his watches thereafter, it was also adopted by Omega and later by his protégé, Roger Smith.