Ernest Guinand (c1810-1879) was an important master watchmaker from Le Locle, who, together with the famous Auguste Grether, specialized in the production of tourbillon carriages.
According to the records of the Neuchâtel Observatory, Guinand's first tourbillons were made between 1865 and 1867. Many of them were tested at the Observatory, amongst which two were awarded the second and third prizes in the 1879 contest, Category C for pocket chronometers featuring bascule (lever) escapements.
Although his carriages were often not signed, they are easily identified by their distinctive A-shaped frames (see Reinhard Meis Das Tourbillon, p. 43, Z44 "Guinand 1"). They were mostly fitted with pivoted detent escapements, such as the present watch, some with lever escapements.
Guinand supplied his tourbillons to renowned watchmakers such as Girard-Perregaux and Montandon but was supposedly also commissioned by Patek Philippe with the design of their first tourbillon regulator in 1864.