BY A. MAULT. 11 



conseqvieuce, as the depth of water in the harboui* is such 

 that the comparatively small rise and fall of tide does not 

 much affect sailing arrangements. 



It is, however, very desirable that the observations to be 

 taken should be as complete as those given by Captain 

 Oldham, and I would press on the Society the desirability of 

 co-operating with the Marine Board to secure this. The 

 importance of the registration of the actual tidal action 

 speaks for itself, and equally so does the necessity of com 

 paring continually such action with the age and position of 

 the moon. The force and direction of the wind have also 

 an influence that must be noted. In connection with this I 

 may mention that during this month's observations, as shown 

 on the large diagram, the highest tides occurred with the 

 wind blowing from north, and north-easterly points — that is 

 more or less down the Channel. The barometer should also 

 be carefully observed, if a mean sea level is to be fixed, as a 

 fall of one inch in the barometer means a rise of 20 inches 

 in the sea level. 



Another important matter can only be secured by the co- 

 operation of the Marine Board; — the progress of the tide 

 wave round the coast. I would suggest that they be asked 

 to get their lighthouse men to keep a register of the actual 

 times of high and low water as nearly as can be ascertained 

 by them during all the time that registers are being kept 

 here. This is a matter of general interest. 



I have to apologise to the Society for the presentation of 

 such a meagre paper, but must plead the engrossing nature 

 of my other occupations, and the time that the preparation 

 of the diagrams has taken. But I hope I have said enough 

 to show the desirability of pursuing investigation in this 

 channel. 



DiscTJSsioisr. 



Mr. A. Gr. Webster stated that the Marine Board would 

 be willing to render any assistance in its power. 



Sir Lambert Dobson said that a namesake of his, who 

 was head-master of the High School, had manufactui-ed an 

 automatic tide gauge himself, and kept a register of tides for 

 some time. He could not say when it was, but he thought it 

 would be about 1853. 



Mr. W. E. Shoobridge stated that at one time he used to 

 register the tide in the Derwent, and found it varied very 

 much, the lowest tides occurring about February and March. 



His Excellency thought it would be very important to 

 have the observations in regard to the tidal wave around the 



