Measurements of the Height of a Large Drop of Mercury

Abstract

IN determining the surface tension of mercury and other liquid metals, many workers have used the method of measuring the height from the maximum section to the summit of a large drop. Most agree as to the method of setting on the maximum section, but a variety of ways are used to define the top of the drop. Two recent papers¹ describing measurements made after using every care to obtain pure mercury and high vacuum, and with no essential difference in technique except in the method of defining the summit of the drop, give respectively 515 ± 6.8 dynes and 432.2 ± 0.3 dynes for the maximum surface tension of mercury at 31°C. In view of this discrepancy and the fact that it corresponds to a difference of only about 0.2 mm. in height of the drop, the following notes on methods tried out in this laboratory may be pertinent.