Velocity of Transmission of Disturbances through Sea-water. 535 



account for our results — nor, indeed, would this view be consistent 

 with the remarks made on the subject of choosing Tait's formulae. 

 On the other hand, we have reasons for thinking that after the 

 pressure increases beyond a certain point, the resilience may increase 

 with very great rapidity; if this is the case, it will explain our 

 results, the wave would rush past the first gauge, and then slow 

 clown with comparative suddenness. 



It may be remembered that with respect to Class A, there was 

 some evidence in favour of thinking that the velocity depends largely 

 on the temperature of the water ; this conclusion was not borne out 

 by Class B, where the temperature was slightly higher. Without 

 pretending to say that the evidence advanced is of any real import- 

 ance, depending as it does on single observations encumbered with 

 their private peculiarities, we may note that it would not be at all 

 unlikely for velocities measured as we measured these to have large 

 positive temperature coefficients. There is every reason to suppose 

 that under the conditions of our experiments the viscosity of the 

 water will be an important factor in determining the rate of decay of 

 the disturbance as it is propagated outwards. Now, of all the 

 physical properties of water, viscosity is the one which varies most 

 rapidly with temperature, and, consequently, it is not unlikely that 

 the decay of amplitude, and hence velocity in the disturbance, may 

 depend to a great extent on the temperature. 



In addition to the wave of great amplitude whose velocity has 

 formed the subject of this paper, there are, in all probability, waves 

 of varying degrees of amplitude and velocity resulting from the 

 explosion. These waves, together with the final group, having 

 practically the velocity of sound do not, at present, present any 

 features of particular interest 



