Description

A Daltons law experiment instrument. An example can be found in the catalogue of E. Leybold’s nachfolger. 

That in a vessel filled with air of atmospheric density as much vapour is formed as in a vacuum. With stand and funnel cock.

The glass sphere an cock are removed and the two tubes filled with dry mercury, the lower cock being closed. The glass balloon is then filled with the gas to be experimented with, e.g. nitrogen and screwed on to the tube. All three cocks are opened so that mercury flows out and the wider tube is filled with the gas, the cocks being then closed: mercury is then poured into the smaller tube until the levels in both are equal. The gas is now under atmospheric pressure. The bulb is replaced by the funnel cock and a little of the liquid poured into the latter. After nothing the level of the mercury the funnel cock is turned through 180⁰ and the liquid admitted into the wider tube. The turning of the cock must be replaced until on admitting a fresh quantity of the liquid the level of the mercury remains unchanged. The difference in the heights measures the increase of pressure. With this apparatus such liquids as dissolve the cement or grease must not be used.

Height: 116 cm.