The peculiarity in this invention consists in the forming of convenient and perfectly air-tight stoppers, in a substance not liable to corrode. It is effected by bringing into contact two circular discs of glass, the flat surfaces of which being ground to true planes, are opposed to each other and united by a central pivot, rivetted to a bar of metal fixed above them, across the mouth of the vessel. Each plate has an Aperture of proper dimensions for dipping the pen, and the upper plate is provided with two projecting studs, at equal distances from the central pivots. The thumb and fore finger being applied to these two studs, the upper disc is easily turned either to the right or left; one way brings the apertures opposite to each other, which opens the inkstand, and being moved the other way, the unperforated part of the upper disc is slided over the stationary aperture of the lower, and perfectly closes it. The rubbing surfaces are slightly oiled, which renders the motion smooth and easy, and the sealing perfect.

Fig. 1. affords a perspective view of an inkstand of this kind, made of very thick cut glass; the discs or stoppers of which are surrounded by a metallic ring, and kept down in their places by an horizontal metallic bar, into which the pivot of the discs is fitted.

In this figure it will be perceived that the inkstand is shut, the aperture in the upper plate being over the unperforated part of the lower. On turning the studs a quarter round, they are stopped by striking against the cross bar, when the two holes coincide, (as shown in the annexed sections), by which the inkstand is opened. Underneath the bar (which is shown by a transverse section) a steel spring is fixed,which keeps the discs in close yet easy contact. The advantage of this contrivance consists in the facility and expedition with which the inkstand may be opened and closed air tight, the simplicity of the construction, and the incorruptibility of the materials.