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XV. Discussion of Tide Observations made at Liverpool. By John William Lubbock 



Esq. V.P. and Treas. R.S. 



Received and Read June 18, 1835. 



JlJY permission of the British Association for the Advancement of Science, I am 

 enabled to present to the Society a discussion by M. Dessiou * of 13,327 observa- 

 tions of the tides made at Liverpool between the 1st of January 1774 and the 31st of 

 December 1792. These observations, which were made by Mr. Hutchinson, Dock- 

 master at that place, belong to the Lyceum at Liverpool, and they were granted 

 with the greatest readiness and liberality by the Committee of that Institution, upon 

 the application of Mr. Whewell and myself, for the purposes of the present inquiry. 



Mr. Hutchinson recorded the solar time of high water, and the height of the tide in 

 feet and inches, at the Custom-House Dock gates, together with the direction and 

 strength of the wind, and the state of the weather ; also, during a great portion of the 

 time, the height of the barometer and thermometer. 



The following note is prefixed to the first book of these valuable observations : 

 "I'hese five years' observations upon the tides were made from solar time, and the 

 winds from the true meridian, and their velocity judged according to Mr. Smeaton's 

 rule, our great storms going at the rate of sixty miles an hour ; the thermometer kept 

 in doors, at the head of a staircase four stories high ; by William Hutchinson, at 

 the Old Dock gates, Liverpool." 



'f he following note is appended at the conclusion : "These observations, made 

 from the beginning of 1768 to August 10, 1793, make twenty-five years, seven months 

 and ten days, which I have given to our Library, exclusive of the 3000 observations 

 given to Messrs. Holdens, to make their tide tables, as mentioned in their preface 

 to them. I could not continue any longer to make observations, for want of the com- 

 mand of our dock gate men and gauge rod to take the night tides. Having resigned 

 my place as Dockmaster, this journal ceases by me, William Hutchinson." 



These notes contain the only information with respect to the manner in which the 

 observations were made which the books afford. The observations appear to have 

 been carefully conducted, but no precautions are stated to have been taken to ensure 

 the accuracy of the time ; and it is difficult to fix whether by solar time is meant 

 apparent solar or mean solar time : this point ought not to have been left in doubt. 

 This point of uncertainty does not however, in any sensible degree, affect the Tables 

 VI., Vn., VIII., and IX., which have reference to the variations of the moon's parallax, 



* M. Dessiou has received from the British Association more than £100 for this work. 



