The Rolex Prince, launched around 1928, is synonymous with a period of huge social and economic change. Everything about this watch was new; the layout of this newly patented watch movement allowed Rolex to use a rectangular case design instead of the traditional round case. This type of case allowed for a much larger dial, with an oversized and very legible subsidiary seconds dial.
Two models were introduced at that time, the more subdued rectangular sided ‘doctor’s watch’, the reference 1343, and the flared sided Brancard, such as this present reference 1490. This particular watch also features an attractive black dial which is perfectly offset by the yellow gold case.
Illustration of similar examples please see "The Best of Time, Rolex Wristwatches", by James M. Dowling and Jeffrey P. Hess, P. 110 - P. 133.