Cork Borer from Brass Tube: Edge Filed Like Two Gouges Back to Back, Steel Wire Handle (Soward, Amateur Work, 1881)

"This latter instrument is simply a piece of brass tube about 4 in. long, and of a diameter suited to the hole required."

Cut about 4 in. (100 mm) of brass tube whose outside diameter matches the hole you need (he takes 3/8 in., about 10 mm, for a glass tube). Square both ends.

File one end on the outside only, all round, to a thin cutting edge: like two gouges put together with their hollow sides facing (B in his fig. 7). Leave the bore untouched.

Fit a small brass ring or flange round the other end to strengthen it (D in fig. 7). Ours: cut it from brass sheet and soft-solder it on.

Below the flange, drill a hole straight across the tube for a piece of steel wire. Push the wire through so it stands at right angles to the tube as a handle (C in fig. 7, drawn with a head on one end).

From Alfred W. Soward, "Filters: Their Construction and Maintenance" I, **Amateur Work, Illustrated**, vol. I (1881), pp. 131-133 and fig. 7 (checked on the archive.org scan amateurworkillus11881lond). To use it, hold the cork's small end against a wall or the bench edge, press on the centre of the large end and turn like a gimlet, giving the cork a quarter turn left after each quarter turn of the borer right. A bought set of four then cost 1s. He does not say how the flange is fixed: soft solder, the metric figures and the tools are ours.