ON TIDAL OBSERVATIONS. 



131 



The fact exists ; but the immediate cause of this occurrence your Com- 

 mittee are still unable to determine, and must therefore leave the solutioa 

 for further light and knowledge to be brouglit to bear upon it. 



The nearest approximation to this fixed law occurs at Goole, where we 

 find that when the tide has reached the 8-feet mark of the tide-gauge, or 

 4-177 feet above the mean rise of the sea at Live -pool, the average time to 

 high water, as observed over twenty-seven tides aud recorded in the following 

 Tables, is 2 hours and 6 minutes, but the extreme variation is found to ex- 

 tend from 1 hour and 35 minutes to 2 hours and 25 minutes. 



In analyzing or reducing the observations of the various stations, the fol- 

 lowing are the results on the fifty-four tides in reference to the zero of each 



Place. 



Nabum Lock 

 Goole 



Gainsborough 

 HuU 



Mean rise 



oyer the 



entire 



observations. 



ft. in. 



6 4 



11 



5 8 



16 3 



Highest tide | Lowest tide 



above zero of abovB zero ol 



gauge. i gauge. 



ft. in. 



10 11 



16 9 



8 11 



26 4 



ft. in. 



4 10 

 10 3 



3 

 20 3 



Highest low 



water above 



zero of gauge, 



ft. in. 



4 3 



3 10 



3 



10 4 



Lowest low 

 water above 

 zero of gauge. 



ft. in. 



1 3 



2 3 



0\ 



_ The following Table gives the greatest rise of tide during the observa- 

 tions above the Ordnance datum at each station : — 



It will be seen by the above that the highest surface-rise occurred on the 

 9th of May at Naburn Lock and at Gainsberough, and that at Goole and 

 Hull on the_25th of May. The excessive height at Naburn Lock and Gains- 

 borough taldng place on the above date, indicates a considerable flush in the 

 rivers at the time from' rains which had fallen previously in districts above 

 the poLiatsof observation. The superior rise at HuU and Goole only indicates 

 tidal influence. 



The following Table gives the time at each station the tides on an average 

 requii-e in rising and falling : — 



k2 



