Pearson — Observations of the Tides at Liverpool. 351 



LVIII. — Three Teaes' Observation's oe the Tides at Liveepool 

 (Fleetwood). By tlie Eev. James Peakson, M.A., F.R.A.S., late 

 Scholar (15th Wrangler) of Trinity College, Cambridge, Vicar of 

 Fleetwood. 



[Read, December 13, 1880.] 



It is now two years ago since I last had the honour of addressing the 

 Academy on the above subject, and it is ten years at least since I first 

 began a close application to the study of it. During all this inter- 

 val I have been making a continuous system of observations, and have 

 compared them with the results of theory, so as to form an esact 

 opinion as to whether the method of computation which my own 

 investigation led me to adopt was true to nature. It is a subject 

 which becomes more fascinating the more it is indulged in. Few care 

 to give to it the attention it deserves, and fewer still have the oppor- 

 tunity of noting the effect of barometric changes and atmospheric gra- 

 dients so as to eliminate these disturbing causes from the general 

 effects. Mrs. Somerville designated the state of the theory of the 

 tides in her time as " a reproach to science " ; and even Dr. Whewell, 

 in his "History of the Inductive Sciences," complains of want of 

 success. Under those circumstances there is every encouragement to 

 persevere in the study. Like an unploughed field, it demands cul- 

 tivation, and the more because so few care to work in it. Although 

 recently a renewed effort has been made, and a fresh theory, based on 

 a Harmonic Analysis, has been adopted, aided by a complicated and 

 expensive machine which is to facilitate calculation, yet no practical 

 tables have been forthcoming which may be submitted to the test of 

 experiment, so far at least as one of the most important seaports of 

 our country is concerned, viz., the Port of Liverpool. At this station 

 we have two superimposed tides of 27^ feet mean range arriving at 

 the same instant, or nearly so ; and the force of gravitation may be as 

 plainly seen in action as the movement of the machinery of a watch is 

 discerned by noticing the motion of the seconds-hand. Hitherto the 

 only tide-tables put into circulation have been (1) those published in 

 the Isle of Man, (2) those originated by the Eev. George Holden, M.A., 

 and printed in Liverpool, and (3) the Admiralty tables issued in Lon- 

 don. The first are of more recent date than the second, but the 

 mode of computation adopted in producing them is kept an inviolable 

 secret. On this point Dr. Whewell writes as follows ("History of 

 the Inductive Sciences," vol. ii., p. 255) : — " Art, in this instance, 

 having cast off her legitimate subordination to Science, or rather, 

 being deprived of the guidance which it was the duty of Science to 

 afford, resumed her ancient practices of exclusiveness and mystery. 

 Liverpool, London, and other places, had their tide-tables, constructed 

 by undivulged methods, which methods, in some instances at least, 



