A superb & rare mid 19th century Charles Hull direct pressure corkscrew. It's in good working condition with some nibbles on the handle. The wire helix is full length, it releases from the mechanism when you pull the button. It measures 6 3/4". It's marked on the barrel "G Hull's Patent". It's marked around the brass button "Chas Hull's Presto Corkscrew". 

According to Ferd Peter's book - Mechanical Corkscrews, the patent for this

corkscrew was never found, although similar corkscrew designs were patented in

America (Van Gieson C1867 & Bussey C1868), the former was produced in Charles

Hull's Birmingham factory.