One of only two known examples in a half-hunting case and preserved in extremely good condition, the present watch is one of fewer than two dozen recorded independent dead second watches by Patek Philippe, including the very first examples made by Patek and Czapek.
A similar example is illustrated in Patek Philippe Museum - Patek Philippe Watches Volume I, p. 243, p. 264.
Roberto Pietro Kohlschitter was born in Monza in 1866. He was hired by the "Ufficio Idrografico" - the Italian Hydrographic Institute - in December 1885. In 1910 Kohlschitter received a silver medal for his "services to nautical sciences". He was still working in 1923. It is not known if Roberto was in any way related to the manufacturer of chronometers and precision instruments in Milan, Giuseppe Kohlschitter.