Split seconds (ratrapante) timer. Beautiful enamel dial. Scales both in 60 seconds and decimal minute. Counting up to 30 minutes. Signed on movement “Minerva” and “Minerva Watch Co Swiss, (on inside back case) 914912”. Minerva logo stamped, permanent running, 15 jewels (?) column wheel movement. Pre Incabloc (no shock absorber), ca 1940s. 57mm diameter.