178 Transactions of the Royal Society of Victoria. 



of gravity of the earth acting on the oceans, the tide thus 

 producible would be less, therefore, than one-millionth of 

 500 feet. This would be a mere ripple on the actual tide. 



When the weight of air over any place is greater than the 

 average for that place at that time of the year, it produces, 

 if on the ocean, a hollow in its surface, and of course there 

 must be a corresponding rise around this hollow. Now, the 

 moon weakens the force of gravity of the earth under the 

 moon (and on the opposite side of the earth also), and the 

 weight or pressure of water under the moon is less than the 

 weight or pressure of water at places on the earth (oceanic 

 regions) at right angles to a line drawn from the moon's 

 centre to the earth's centre. The greater pressure of water 

 at places a great distance from the vertical moon will 

 therefore cause a hollow there and a rise, wave, or tide 

 under the moon, that is, if the action of the moon could 

 immediately produce its full effect. Time must, however, 

 be allowed to overcome the inertia of the water. The rise, 

 or tidal wave of water therefore follows some time after the 

 vertical moon. 



The reasoning in this paper therefore shows : — First, that 

 it is impossible for the slight attractive force of the moon to 

 hft up a body of water directly against the vastly greater 

 force of gravity of the earth drawing this water down. 

 Second, that it is the greater weight of water at a great 

 distance from the moon's vertical, so to speak, that makes a 

 hollow there, and a corresponding rise nearer the moon's 

 vertical. 



