Stopcock and evacuation tube

Laboratory glassware, 200 mL conical flask holding a custom made stopcock and tube arrangement. Conical flask made by James A Jobling & Co Ltd., Wear Glass Works, Millfield, Sunderland, England, date 1922-1975. The flask has, near the mouth, a circular trademark in green with "PYREX" at the top, "MADE IN ENGLAND" at the bottom and the "JP" monogram at both sides. Below the circular trademark is the capacity “200 ML”, also in green. In the mouth of the flask sits a custom made tube with a ground glass cup at the top, leading down to a two-way stopcock and then into a tube. Just below the ground glass cup there is what appears to be a capilliary valve. The tube leading away from the stopcock is enclosed in a glass surrounding that could be evacuated, although the evacuation tube is broken.