The authors describe experiments concerned with the limiting negative pressure (that is, tension) which water can sustain when stressed dynamically by propagating a pulse of tension through a vertical column of the liquid. The effect of boiling and deionization increased the ability of the water to withstand tension. A single sample of water was subjected to repeated tensile failure at regular time intervals and it was found that the breaking tension that could be sustained tended progressively to an upper limit of about 11.0 atm as this type of stressing proceeded. The breaking tension is a maximum at around the temperature corresponding to the maximum density of water.

An estimate is made of the ultimate tensile strength of water with data from previously reported isochores obtained using the Berthelot tube method. The agreement with the theoretical values predicted by Temperley's theory (1947) is most satisfactory.

The authors present an account of experiments to determine the effect of polyacrylamide additives on the breaking tension of water. Firstly, a new strain-gauge method for measuring the static breaking tension of a liquid enclosed in a stainless steel Berthelot tube is described. Secondly, the results obtained for the static breaking tensions of dilute polyacrylamide solutions are reported. Thirdly, the results found for the dynamic breaking tensions of these solutions are also given. It is found that the presence of the polymer additive in the water makes no different to the values of the static breaking tension but leads to a reduction in the values of the dynamic breaking tension.