152 KEPORT— 1886. 



Dover and at Calais) 5'50 metres below the Frencli ' zei'O du nivellement ' 

 (Bourdaloue). 



Since tlie meeting of last year the Committee, considering that these 

 four years' observations would, in their entirety, form too large a mass 

 for publication, decided upon specially preparing a more limited portion 

 of these observations. 



After much consideration, as the records of the year 1883 appeared 

 on the "whole to be the most reliable and complete, selections were made 

 of a fortnight before and after the winter, and also at the summer solstice, 

 and of a similar period at the vernal and at the autumnal equinox in that 

 year ; those times appearing to offer most points of intei'est. 



The high water and low water observations during these four periods 

 are appended to this Report, as also a continuous diagram of the two sets 

 of observations during one of the periods (the vernal equinox). 



It has been repeatedly felt by the Committee that there are many 

 points of interest which present themselves in the four-year period em- 

 braced by the entire records which are beyond the scope of the present 

 Committee, and which would require a complete and exhaustive examina- 

 tion of those records to fully disclose them. 



Your Committee, therefore, before closing their labours, would suggest, 

 that, if the Committee ' On the Harmonic Analysis of Tidal Observations' 

 considered the investigation of the tides of the English Channel to be 

 within the scope of their inquiiy, the present Committee would, with the 

 consent of the respective authorities, be glad to place at the disposal of 

 the Committee ' On Harmonic Analysis ' the records of the Dover and 

 of the Ostend tide-gauges ; as also any further information in their 

 possession. 



In the earlier stages of the work of the present Committee it was 

 hoped that some of the records of the self- registering tide gauges on the 

 French coast would have been included in the comparison of the various 

 tidal observations in the English Channel. It was found, however, that 

 the difficulty to obtain records continuously throughout the four-year 

 period selected was very considerable. With the more limited periods of 

 four separate months in one year the difficulty is very materially reduced. 



It is still possible, that a comparative record of at least one of these 

 shorter periods from a point on the Fi-ench coast may yet arrive so as to 

 be presented with the other observations accompanying this Report. 



In conclusion the Committee request, that the thanks of the British 

 Association be conveyed to the President of the Board of Trade, and to 

 the Minister of Public Works of Belgium for their courtesy in placing at 

 the disposal of the Committee the records of the tide-gauges at Dover 

 and at Ostend respectively. Also to the several other authorities and 

 private individuals, for the kind assistance they have afforded to the Com- 

 mittee during the course of their investigations. 



